--- a/src/SbpOperators/volumeops/derivatives/second_derivative.jl	Mon Mar 02 14:06:41 2026 +0100
+++ b/src/SbpOperators/volumeops/derivatives/second_derivative.jl	Mon Mar 02 14:11:32 2026 +0100
@@ -1,24 +1,24 @@
 """
-second_derivative(g::TensorGrid, stencil_set, direction)    
-second_derivative(g::EquidistantGrid, stencil_set, direction)
+second_derivative(g::TensorGrid, stencil_set, dim)
+second_derivative(g::EquidistantGrid, stencil_set, dim)
 
 Creates the second derivative operator `D2` as a `LazyTensor`
 
 `D2` approximates the second-derivative d²/dξ² on `g` along the coordinate
-dimension specified by `direction`.
+dimension specified by `dim`.
 
 See also: [`VolumeOperator`](@ref), [`LazyTensors.inflate`](@ref).
 """
-function second_derivative(g::TensorGrid, stencil_set, direction)
-    if direction ∉ 1:ndims(g)
-        throw(DomainError(direction, "Direction must be inside [0, $(ndims(g))]."))
+function second_derivative(g::TensorGrid, stencil_set, dim)
+    if dim ∉ 1:ndims(g)
+        throw(DomainError(dim, "Direction must be inside [0, $(ndims(g))]."))
     end
-    D₂ = second_derivative(g.grids[direction], stencil_set)
-    return LazyTensors.inflate(D₂, size(g), direction)
+    D₂ = second_derivative(g.grids[dim], stencil_set)
+    return LazyTensors.inflate(D₂, size(g), dim)
 end
 
-function second_derivative(g::EquidistantGrid, stencil_set::StencilSet, direction)
-    return second_derivative(TensorGrid(g), stencil_set, direction)
+function second_derivative(g::EquidistantGrid, stencil_set::StencilSet, dim)
+    return second_derivative(TensorGrid(g), stencil_set, dim)
 end
 
 """