Desire wife to join worker (4)
I believe the answer is:
want
'desire' is the definition.
(I know that desire is a more specific form of the action wish)
'wife to join worker' is the wordplay.
'wife' becomes 'w' (abbreviation).
'to join' is a charade indicator (letters next to each other).
'worker' becomes 'ant' (worker is a type of ant).
'w'+'ant'='WANT'
(Other definitions for want that I've seen before include "Need or desire" , "Wish" , "Lack, desire" , "Desire to possess" , "'Wilful waste makes woeful . . . .'" .)