Garment in ancient Rome (4)
I believe the answer is:
'garment in ancient rome' 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 gents' cloak" , "Old-style dress" , "Classical garment" , "Roman male garb" , "This ancient robe might get your goat" .)