Skin-tight garment (7)
I believe the answer is:
leotard
'skin-tight garment' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for leotard that I've seen before include "One-piece garment worn by acrobat" , "Body suit for dancers" , "Dancers might wear this" , "Do alter the dancer's garment" , "Close-fitting garment worn by dancers" .)