A sailor giving an officer a parcel (7)
I believe the answer is:
matelot
'a sailor' is the definition.
(I've seen this before)
'giving an officer a parcel' is the wordplay.
'giving' means one lot of letters go next to another.
'an officer' becomes 'mate' (mate is a kind of officer).
'a parcel' becomes 'lot' (lot is a kind of parcel).
'mate'+'lot' is 'MATELOT'.
(Other definitions for matelot that I've seen before include "One at sea" , "Rating" , "Sailor (slang from French)" , "A lot met (anag) - sailor" , "seafarer" .)