Insect swallows fruit for nourishment (7)
I believe the answer is:
aliment
'for nourishment' is the definition.
(synonyms)
'insect swallows fruit' is the wordplay.
'insect' becomes 'ant' (ant is a kind of insect).
'swallows' indicates putting letters inside.
'fruit' becomes 'lime' (lime is a kind of fruit).
'ant' placed around 'lime' is 'ALIMENT'.
(Other definitions for aliment that I've seen before include "Nourishment" , "Something which nourishes - meal tin (anag)" , "Sustenance" , "Old word for food" .)