Worker consumes citrus fruit for nourishment (7)
I believe the answer is:
aliment
'nourishment' is the definition.
('aliment' can be a synonym of 'nourishment')
'worker consumes citrus fruit' is the wordplay.
'worker' becomes 'ant' (worker is a type of ant).
'consumes' indicates putting letters inside.
'citrus fruit' becomes 'lime' (lime is a kind of citrus fruit).
'ant' placed around 'lime' is 'ALIMENT'.
'for' is the link.
(Other definitions for aliment that I've seen before include "Nourishment" , "Something which nourishes - meal tin (anag)" , "Sustenance" , "Old word for food" .)