Rename
Rename oldName, newName
The Rename operation renames waves, strings, or numeric variables from oldName to newName.
Parameters
oldName may be a simple object name or a data folder path and name. newName must be a simple object name.
Details
You cannot rename an object using a name that already exists. The following will result in an error:
Make wave0, wave1
// Rename wave0 and overwrite wave1.
Rename wave0, wave1 // This will not work.
However, you can achieve the desired effect as follows:
Make wave0, wave1
Duplicate/O wave0, wave1; KillWaves wave0