Present in box, unopened (5)
I believe the answer is:
offer
'present' is the definition.
(thesaurus)
'box unopened' is the wordplay.
'box' becomes 'coffer' (coffer is a kind of box).
'unopened' means to remove the first letter.
'coffer' with its first letter removed is 'OFFER'.
'in' acts as a link.
(Other definitions for offer that I've seen before include "Tender, volunteer" , "Provide; reduced price" , "(Suggestion of) gift" , "Proposition" , "Make available for sale" .)