Stretchy costume fat member brought back in (7)
I believe the answer is:
leotard
'stretchy costume' is the definition.
'leotard' can be an answer for 'costume' (costume worn by a dancer). I'm not certain of the 'stretchy' bit.
'fat member brought back in' is the wordplay.
'fat' becomes 'lard' (lard is a kind of fat).
'member' becomes 'toe' (toe is a kind of member).
'brought back' shows that the letters should be reversed in order.
'in' indicates putting letters inside.
'toe' written backwards gives 'eot'.
'lard' enclosing 'eot' is 'LEOTARD'.
Can you help me to learn more?
(Other definitions for leotard that I've seen before include "Stretchy one-piece garment" , "Garment for gymnast" , "Dance/exercise garment" , "Garment worn by ballet dancers" , "Tight-fitting garment, for gymnasts say" .)