diff --git a/applications/utilities/mesh/generation/snappyHexMesh/snappyHexMesh.C b/applications/utilities/mesh/generation/snappyHexMesh/snappyHexMesh.C
index 6e417abc1e..18d22cc1a3 100644
--- a/applications/utilities/mesh/generation/snappyHexMesh/snappyHexMesh.C
+++ b/applications/utilities/mesh/generation/snappyHexMesh/snappyHexMesh.C
@@ -38,7 +38,7 @@ Description
 #include "searchableSurfaces.H"
 #include "refinementSurfaces.H"
 #include "refinementFeatures.H"
-#include "shellSurfaces.H"
+#include "refinementRegions.H"
 #include "decompositionMethod.H"
 #include "noDecomp.H"
 #include "fvMeshDistribute.H"
@@ -1005,7 +1005,7 @@ int main(int argc, char *argv[])
     // ~~~~~~~~~~~~~~~~~~~~~~
 
     Info<< "Reading refinement regions..." << endl;
-    shellSurfaces shells
+    refinementRegions shells
     (
         allGeometry,
         refineDict.found("refinementRegions")
diff --git a/src/mesh/snappyHexMesh/Make/files b/src/mesh/snappyHexMesh/Make/files
index 0681b173fb..0e5f5e743c 100644
--- a/src/mesh/snappyHexMesh/Make/files
+++ b/src/mesh/snappyHexMesh/Make/files
@@ -19,7 +19,7 @@ meshRefinement/patchFaceOrientation.C
 refinementFeatures/refinementFeatures.C
 refinementSurfaces/surfaceZonesInfo.C
 refinementSurfaces/refinementSurfaces.C
-shellSurfaces/shellSurfaces.C
+refinementRegions/refinementRegions.C
 trackedParticle/trackedParticle.C
 
 externalDisplacementMeshMover/displacementMeshMoverMotionSolver.C
diff --git a/src/mesh/snappyHexMesh/meshRefinement/meshRefinement.C b/src/mesh/snappyHexMesh/meshRefinement/meshRefinement.C
index 7e2f3b729f..4575a3ab28 100644
--- a/src/mesh/snappyHexMesh/meshRefinement/meshRefinement.C
+++ b/src/mesh/snappyHexMesh/meshRefinement/meshRefinement.C
@@ -1165,7 +1165,7 @@ Foam::meshRefinement::meshRefinement
     const bool overwrite,
     const refinementSurfaces& surfaces,
     const refinementFeatures& features,
-    const shellSurfaces& shells
+    const refinementRegions& shells
 )
 :
     mesh_(mesh),
@@ -2242,7 +2242,7 @@ void Foam::meshRefinement::distribute(const mapDistributePolyMesh& map)
         treeBoundBox& bb = meshBb[0];
         bb = treeBoundBox(mesh_.points()).extend(1e-4);
 
-        // Distribute all geometry (so refinementSurfaces and shellSurfaces)
+        // Distribute all geometry (so refinementSurfaces and refinementRegions)
         searchableSurfaces& geometry =
             const_cast<searchableSurfaces&>(surfaces_.geometry());
 
diff --git a/src/mesh/snappyHexMesh/meshRefinement/meshRefinement.H b/src/mesh/snappyHexMesh/meshRefinement/meshRefinement.H
index 1b02ba5a38..ea53c5c4e2 100644
--- a/src/mesh/snappyHexMesh/meshRefinement/meshRefinement.H
+++ b/src/mesh/snappyHexMesh/meshRefinement/meshRefinement.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2021 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -63,7 +63,7 @@ class mapDistributePolyMesh;
 class decompositionMethod;
 class refinementSurfaces;
 class refinementFeatures;
-class shellSurfaces;
+class refinementRegions;
 class removeCells;
 class fvMeshDistribute;
 class searchableSurface;
@@ -178,7 +178,7 @@ private:
         const refinementFeatures& features_;
 
         //- All shell-refinement interaction
-        const shellSurfaces& shells_;
+        const refinementRegions& shells_;
 
         //- Refinement engine
         hexRef8 meshCutter_;
@@ -588,7 +588,7 @@ public:
             const bool overwrite,
             const refinementSurfaces&,
             const refinementFeatures&,
-            const shellSurfaces&
+            const refinementRegions&
         );
 
         //- Disallow default bitwise copy construction
@@ -639,7 +639,7 @@ public:
             }
 
             //- Reference to refinement shells (regions)
-            const shellSurfaces& shells() const
+            const refinementRegions& shells() const
             {
                 return shells_;
             }
diff --git a/src/mesh/snappyHexMesh/meshRefinement/meshRefinementRefine.C b/src/mesh/snappyHexMesh/meshRefinement/meshRefinementRefine.C
index 72f1106e12..ada066e85c 100644
--- a/src/mesh/snappyHexMesh/meshRefinement/meshRefinementRefine.C
+++ b/src/mesh/snappyHexMesh/meshRefinement/meshRefinementRefine.C
@@ -29,7 +29,7 @@ License
 #include "Time.H"
 #include "refinementSurfaces.H"
 #include "refinementFeatures.H"
-#include "shellSurfaces.H"
+#include "refinementRegions.H"
 #include "faceSet.H"
 #include "decompositionMethod.H"
 #include "fvMeshDistribute.H"
diff --git a/src/mesh/snappyHexMesh/shellSurfaces/shellSurfaces.C b/src/mesh/snappyHexMesh/refinementRegions/refinementRegions.C
similarity index 97%
rename from src/mesh/snappyHexMesh/shellSurfaces/shellSurfaces.C
rename to src/mesh/snappyHexMesh/refinementRegions/refinementRegions.C
index 7e0923fa9b..beedc6d435 100644
--- a/src/mesh/snappyHexMesh/shellSurfaces/shellSurfaces.C
+++ b/src/mesh/snappyHexMesh/refinementRegions/refinementRegions.C
@@ -23,7 +23,7 @@ License
 
 \*---------------------------------------------------------------------------*/
 
-#include "shellSurfaces.H"
+#include "refinementRegions.H"
 #include "refinementSurfaces.H"
 #include "searchableSurfaces.H"
 #include "orientedSurface.H"
@@ -36,7 +36,7 @@ namespace Foam
 
 template<>
 const char*
-NamedEnum<shellSurfaces::refineMode, 5>::
+NamedEnum<refinementRegions::refineMode, 5>::
 names[] =
 {
     "inside",
@@ -48,13 +48,13 @@ names[] =
 
 }
 
-const Foam::NamedEnum<Foam::shellSurfaces::refineMode, 5>
-    Foam::shellSurfaces::refineModeNames_;
+const Foam::NamedEnum<Foam::refinementRegions::refineMode, 5>
+    Foam::refinementRegions::refineModeNames_;
 
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
-void Foam::shellSurfaces::setAndCheckLevels
+void Foam::refinementRegions::setAndCheckLevels
 (
     const label shelli,
     const dictionary& dict
@@ -205,7 +205,7 @@ void Foam::shellSurfaces::setAndCheckLevels
 }
 
 
-void Foam::shellSurfaces::orient()
+void Foam::refinementRegions::orient()
 {
     // Determine outside point.
     boundBox overallBb = boundBox::invertedBox;
@@ -279,7 +279,7 @@ void Foam::shellSurfaces::orient()
                     // sideness which should not be set at this point.
                     // !!Should check!)
 
-                    Info<< "shellSurfaces : Flipped orientation of surface "
+                    Info<< "refinementRegions : Flipped orientation of surface "
                         << s.name()
                         << " so point " << outsidePt << " is outside." << endl;
                 }
@@ -289,7 +289,7 @@ void Foam::shellSurfaces::orient()
 }
 
 
-Foam::scalar Foam::shellSurfaces::interpolate
+Foam::scalar Foam::refinementRegions::interpolate
 (
     const triSurfaceMesh& tsm,
     const triSurfacePointScalarField& closeness,
@@ -314,7 +314,7 @@ Foam::scalar Foam::shellSurfaces::interpolate
 }
 
 
-void Foam::shellSurfaces::findHigherLevel
+void Foam::refinementRegions::findHigherLevel
 (
     const pointField& pt,
     const label shelli,
@@ -515,7 +515,7 @@ void Foam::shellSurfaces::findHigherLevel
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-Foam::shellSurfaces::shellSurfaces
+Foam::refinementRegions::refinementRegions
 (
     const searchableSurfaces& allGeometry,
     const dictionary& shellsDict
@@ -645,7 +645,7 @@ Foam::shellSurfaces::shellSurfaces
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-Foam::label Foam::shellSurfaces::maxLevel() const
+Foam::label Foam::refinementRegions::maxLevel() const
 {
     label overallMax = 0;
 
@@ -658,7 +658,7 @@ Foam::label Foam::shellSurfaces::maxLevel() const
 }
 
 
-void Foam::shellSurfaces::findHigherLevel
+void Foam::refinementRegions::findHigherLevel
 (
     const pointField& pt,
     const labelList& ptLevel,
diff --git a/src/mesh/snappyHexMesh/shellSurfaces/shellSurfaces.H b/src/mesh/snappyHexMesh/refinementRegions/refinementRegions.H
similarity index 95%
rename from src/mesh/snappyHexMesh/shellSurfaces/shellSurfaces.H
rename to src/mesh/snappyHexMesh/refinementRegions/refinementRegions.H
index 4390ad143f..a37b70a794 100644
--- a/src/mesh/snappyHexMesh/shellSurfaces/shellSurfaces.H
+++ b/src/mesh/snappyHexMesh/refinementRegions/refinementRegions.H
@@ -22,19 +22,19 @@ License
     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
 Class
-    Foam::shellSurfaces
+    Foam::refinementRegions
 
 Description
     Encapsulates queries for volume refinement ('refine all cells within
     shell').
 
 SourceFiles
-    shellSurfaces.C
+    refinementRegions.C
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef shellSurfaces_H
-#define shellSurfaces_H
+#ifndef refinementRegions_H
+#define refinementRegions_H
 
 #include "Tuple2.H"
 #include "triSurfaceMesh.H"
@@ -48,10 +48,10 @@ namespace Foam
 class searchableSurfaces;
 
 /*---------------------------------------------------------------------------*\
-                        Class shellSurfaces Declaration
+                        Class refinementRegions Declaration
 \*---------------------------------------------------------------------------*/
 
-class shellSurfaces
+class refinementRegions
 {
 public:
 
@@ -134,7 +134,7 @@ public:
     // Constructors
 
         //- Construct from geometry and dictionary
-        shellSurfaces
+        refinementRegions
         (
             const searchableSurfaces& allGeometry,
             const dictionary& shellsDict
diff --git a/src/mesh/snappyHexMesh/refinementSurfaces/refinementSurfaces.C b/src/mesh/snappyHexMesh/refinementSurfaces/refinementSurfaces.C
index 4ccf1eaed8..1de1166204 100644
--- a/src/mesh/snappyHexMesh/refinementSurfaces/refinementSurfaces.C
+++ b/src/mesh/snappyHexMesh/refinementSurfaces/refinementSurfaces.C
@@ -26,7 +26,7 @@ License
 #include "refinementSurfaces.H"
 #include "Time.H"
 #include "searchableSurfaces.H"
-#include "shellSurfaces.H"
+#include "refinementRegions.H"
 #include "triSurfaceMesh.H"
 #include "labelPair.H"
 #include "searchableSurfacesQueries.H"
@@ -352,7 +352,7 @@ Foam::refinementSurfaces::refinementSurfaces
 // // Pre-calculate the refinement level for every element
 // void Foam::refinementSurfaces::wantedRefinementLevel
 // (
-//     const shellSurfaces& shells,
+//     const refinementRegions& shells,
 //     const label surfI,
 //     const List<pointIndexHit>& info,    // Indices
 //     const pointField& ctrs,             // Representative coordinate
@@ -393,7 +393,7 @@ Foam::refinementSurfaces::refinementSurfaces
 // surface.
 void Foam::refinementSurfaces::setMinLevelFields
 (
-    const shellSurfaces& shells
+    const refinementRegions& shells
 )
 {
     forAll(surfaces_, surfI)
diff --git a/src/mesh/snappyHexMesh/refinementSurfaces/refinementSurfaces.H b/src/mesh/snappyHexMesh/refinementSurfaces/refinementSurfaces.H
index 6e80d07da9..7af9054bb3 100644
--- a/src/mesh/snappyHexMesh/refinementSurfaces/refinementSurfaces.H
+++ b/src/mesh/snappyHexMesh/refinementSurfaces/refinementSurfaces.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2021 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -49,7 +49,7 @@ namespace Foam
 {
 
 class searchableSurfaces;
-class shellSurfaces;
+class refinementRegions;
 class triSurfaceMesh;
 
 typedef List<point> pointList;
@@ -214,7 +214,7 @@ public:
             //- Calculate minLevelFields
             void setMinLevelFields
             (
-                const shellSurfaces& shells
+                const refinementRegions& shells
             );
 
             ////- Helper: count number of triangles per region
diff --git a/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyRefineDriver.C b/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyRefineDriver.C
index 9320e54a74..b33957621f 100644
--- a/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyRefineDriver.C
+++ b/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyRefineDriver.C
@@ -32,7 +32,7 @@ License
 #include "refinementParameters.H"
 #include "refinementSurfaces.H"
 #include "refinementFeatures.H"
-#include "shellSurfaces.H"
+#include "refinementRegions.H"
 #include "mapDistributePolyMesh.H"
 #include "unitConversion.H"
 #include "snapParameters.H"