The vegetable urge works! (8)
I believe the answer is:
eggplant
'the vegetable' is the definition.
(eggplant is a kind of vegetable)
'urge works' is the wordplay.
'urge' becomes 'egg' (I've seen this before).
'works' becomes 'plant' ('plant' can be a synonym of 'works'**).
'egg'+'plant'='EGGPLANT'
(Other definitions for eggplant that I've seen before include "It's also called aubergine" , "Vegetable" , "What goes into moussaka" , "Another word for aubergine" , "Its fruit is aubergine" .)