Gymnast's garment (7)
I believe the answer is:
leotard
'gymnast's garment' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for leotard that I've seen before include "Gymnastic garment" , "One-piece garment worn by acrobat" , "Acrobat costume" , "Garment for gymnast" , "Dance/exercise garment" .)