You could define names at worksheet level. If the worksheet in which
you want to define the name were named X, and you wanted to use the
name A, define the name X!A referring to whatever you want. In
worksheet X when your formulas refer to A, that will refer to the name
A defined in worksheet X. However, you can refer to this name in other
worksheets as X!A. There's no way to hide worksheet-level names from
use in other worksheets.