Wife lives with hot desire (4)
I believe the answer is:
wish
'desire' is the definition.
(wish is a kind of desire)
'wife lives with hot' is the wordplay.
'wife' becomes 'w'.
'lives' becomes 'is' ('be' can be a synonym of 'live').
'with' says to put letters next to each other.
'hot' becomes 'h'.
'w'+'is'+'h'='WISH'
(Other definitions for wish that I've seen before include "Want (to do something)" , "Desire, hope" , "Something desired" , "whim" , "prayer" .)