Pullover, all stretched, covers boiler suit (8)
I believe the answer is:
overalls
'boiler suit' is the definition.
(I've seen this before)
'pullover all stretched covers' is the wordplay.
'covers' indicates a hidden word (I've seen 'covering' mean this).
'OVERALLS' is hidden in the letters of 'pullover all stretched'.
(Other definitions for overalls that I've seen before include "Save roll (anag.)" , "Protective garment" , "Boiler suits" , "Protective wear" , "Boiler suit" .)