Garb for Cato (4)
I believe the answer is:
toga
'garb for cato' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for toga that I've seen before include "Roman raiment" , "Ancient Roman garment" , "Old-style dress" , "Robe for an ancient Roman" , "piece of old clothing" .)