diff --git a/base/array.jl b/base/array.jl
index dc9592b743030..aeda4e649907e 100644
--- a/base/array.jl
+++ b/base/array.jl
@@ -185,13 +185,6 @@ function vect(X...)
     return T[X...]
 end
 
-size(a::Array, d::Integer) = size(a, Int(d)::Int)
-function size(a::Array, d::Int)
-    d < 1 && error("arraysize: dimension out of range")
-    sz = getfield(a, :size)
-    return d > length(sz) ? 1 : getfield(sz, d, false) # @inbounds
-end
-
 asize_from(a::Array, n) = n > ndims(a) ? () : (size(a,n), asize_from(a, n+1)...)
 
 allocatedinline(@nospecialize T::Type) = (@_total_meta; ccall(:jl_stored_inline, Cint, (Any,), T) != Cint(0))
diff --git a/base/bitarray.jl b/base/bitarray.jl
index 5a3469fa7c7a2..9770fe0a336c5 100644
--- a/base/bitarray.jl
+++ b/base/bitarray.jl
@@ -104,11 +104,6 @@ length(B::BitArray) = B.len
 size(B::BitVector) = (B.len,)
 size(B::BitArray) = B.dims
 
-@inline function size(B::BitVector, d::Integer)
-    d < 1 && throw_boundserror(size(B), d)
-    ifelse(d == 1, B.len, 1)
-end
-
 isassigned(B::BitArray, i::Int) = 1 <= i <= length(B)
 
 IndexStyle(::Type{<:BitArray}) = IndexLinear()
diff --git a/base/essentials.jl b/base/essentials.jl
index 84b8f8999038c..59dfe3ded228b 100644
--- a/base/essentials.jl
+++ b/base/essentials.jl
@@ -9,7 +9,7 @@ const Bottom = Union{}
 # Define minimal array interface here to help code used in macros:
 size(a::Array) = getfield(a, :size)
 length(t::AbstractArray) = (@inline; prod(size(t)))
-length(a::GenericMemory) = getfield(a, :length)
+size(a::GenericMemory) = (getfield(a, :length),)
 throw_boundserror(A, I) = (@noinline; throw(BoundsError(A, I)))
 
 # multidimensional getindex will be defined later on
diff --git a/base/genericmemory.jl b/base/genericmemory.jl
index b180462115f41..842d7aacc879c 100644
--- a/base/genericmemory.jl
+++ b/base/genericmemory.jl
@@ -61,13 +61,6 @@ AtomicMemory
 
 using Core: memoryrefoffset, memoryref_isassigned # import more functions which were not essential
 
-size(a::GenericMemory, d::Int) =
-    d < 1 ? error("dimension out of range") :
-    d == 1 ? length(a) :
-    1
-size(a::GenericMemory, d::Integer) =  size(a, convert(Int, d))
-size(a::GenericMemory) = (length(a),)
-
 IndexStyle(::Type{<:GenericMemory}) = IndexLinear()
 
 parent(ref::GenericMemoryRef) = ref.mem
diff --git a/base/indices.jl b/base/indices.jl
index 4f0d9ad14a1b6..0d0e56b12be4b 100644
--- a/base/indices.jl
+++ b/base/indices.jl
@@ -392,7 +392,6 @@ axes1(S::Slice{<:AbstractOneTo{<:Integer}}) = S.indices
 first(S::Slice) = first(S.indices)
 last(S::Slice) = last(S.indices)
 size(S::Slice) = (length(S.indices),)
-length(S::Slice) = length(S.indices)
 getindex(S::Slice, i::Int) = (@inline; @boundscheck checkbounds(S, i); i)
 getindex(S::Slice, i::AbstractUnitRange{<:Integer}) = (@inline; @boundscheck checkbounds(S, i); i)
 getindex(S::Slice, i::StepRange{<:Integer}) = (@inline; @boundscheck checkbounds(S, i); i)
@@ -420,7 +419,6 @@ axes1(S::IdentityUnitRange{<:AbstractOneTo{<:Integer}}) = S.indices
 first(S::IdentityUnitRange) = first(S.indices)
 last(S::IdentityUnitRange) = last(S.indices)
 size(S::IdentityUnitRange) = (length(S.indices),)
-length(S::IdentityUnitRange) = length(S.indices)
 unsafe_length(S::IdentityUnitRange) = unsafe_length(S.indices)
 getindex(S::IdentityUnitRange, i::Integer) = (@inline; @boundscheck checkbounds(S, i); convert(eltype(S), i))
 getindex(S::IdentityUnitRange, i::Bool) = throw(ArgumentError("invalid index: $i of type Bool"))
diff --git a/base/multidimensional.jl b/base/multidimensional.jl
index 1ca25776ba636..fdfcafef1099d 100644
--- a/base/multidimensional.jl
+++ b/base/multidimensional.jl
@@ -485,8 +485,6 @@ module IteratorsMD
 
     size(iter::CartesianIndices) = map(length, iter.indices)
 
-    length(iter::CartesianIndices) = prod(size(iter))
-
     # make CartesianIndices a multidimensional range
     Base.step(iter::CartesianIndices) = CartesianIndex(map(step, iter.indices))
 
@@ -836,7 +834,6 @@ LogicalIndex(mask::AbstractVector{Bool}) = LogicalIndex{Int, typeof(mask)}(mask)
 LogicalIndex(mask::AbstractArray{Bool, N}) where {N} = LogicalIndex{CartesianIndex{N}, typeof(mask)}(mask)
 LogicalIndex{Int}(mask::AbstractArray) = LogicalIndex{Int, typeof(mask)}(mask)
 size(L::LogicalIndex) = (L.sum,)
-length(L::LogicalIndex) = L.sum
 collect(L::LogicalIndex) = [i for i in L]
 show(io::IO, r::LogicalIndex) = print(io,collect(r))
 print_array(io::IO, X::LogicalIndex) = print_array(io, collect(X))
diff --git a/base/strings/basic.jl b/base/strings/basic.jl
index a6015fcd12c99..3bacb3aa12705 100644
--- a/base/strings/basic.jl
+++ b/base/strings/basic.jl
@@ -791,9 +791,8 @@ struct CodeUnits{T,S<:AbstractString} <: DenseVector{T}
     CodeUnits(s::S) where {S<:AbstractString} = new{codeunit(s),S}(s)
 end
 
-length(s::CodeUnits) = ncodeunits(s.s)
 sizeof(s::CodeUnits{T}) where {T} = ncodeunits(s.s) * sizeof(T)
-size(s::CodeUnits) = (length(s),)
+size(s::CodeUnits) = (ncodeunits(s.s),)
 elsize(s::Type{<:CodeUnits{T}}) where {T} = sizeof(T)
 @propagate_inbounds getindex(s::CodeUnits, i::Int) = codeunit(s.s, i)
 IndexStyle(::Type{<:CodeUnits}) = IndexLinear()
diff --git a/stdlib/Random/src/Random.jl b/stdlib/Random/src/Random.jl
index 9e05475b48c20..cc598094b1956 100644
--- a/stdlib/Random/src/Random.jl
+++ b/stdlib/Random/src/Random.jl
@@ -309,7 +309,6 @@ struct UnsafeView{T} <: DenseArray{T,1}
     len::Int
 end
 
-Base.length(a::UnsafeView) = a.len
 Base.getindex(a::UnsafeView, i::Int) = unsafe_load(a.ptr, i)
 Base.setindex!(a::UnsafeView, x, i::Int) = unsafe_store!(a.ptr, x, i)
 Base.pointer(a::UnsafeView) = a.ptr