I think what you are looking for is

Sub Skip_Array_Terms()
Dim oRng As Word.Range
Dim arrWords As Variant
Dim oReplace As Variant
Dim i As Long

    arrWords = Array("A", "B", "C", "D")
    oReplace = Array("Apple", "SKIP", "Cat", "SKIP")

    For i = 0 To UBound(arrWords)
        If Not UCase(oReplace(i)) = "SKIP" Then
            Set oRng = ActiveDocument.Range
            With oRng.Find
                Do While .Execute(FindText:=arrWords(i), MatchWholeWord:=True)
                    oRng = oReplace(i)
                    oRng.Collapse 0
                Loop
            End With
        End If
    Next i
    Set oRng = Nothing
End Sub
Note that access to the Arrays is case sensitive.