Edible seed for vegetable and fruit (6)
I believe the answer is:
peanut
'edible seed' is the definition.
(I've seen this before)
'vegetable and fruit' is the wordplay.
'vegetable' becomes 'pea' (pea is a kind of vegetable).
'and' says to put letters next to each other.
'fruit' becomes 'nut' (nut is a kind of fruit).
'pea'+'nut'='PEANUT'
'for' acts as a link.
(Other definitions for peanut that I've seen before include "Edible seed, may be roasted and salted" , "Groundnut" , "Common snack" , "Salted or dry roasted item" , "Edible seed of Arachis hypogaea" .)