Show chest, topless (5)
I believe the answer is:
offer
'show' is the definition.
(I've seen this before)
'chest topless' is the wordplay.
'chest' becomes 'coffer' (coffer is a kind of chest).
'topless' means to remove the first letter.
'coffer' with its initial letter taken away is 'OFFER'.
(Other definitions for offer that I've seen before include "Proposal (of marriage)" , "Present for acceptance or rejection" , "Chance to buy at reduced price?" , "Proposal; reduced price" , "Tender, make bid for" .)