Wicked desire to get rid of husband (3)
I believe the answer is:
ace
'wicked' is the definition.
(I've seen this before)
'desire to get rid of husband' is the wordplay.
'desire' becomes 'ache' (ache can mean a passionate desire for something).
'to get rid of' indicates named letters should be taken away.
'husband' becomes 'h'.
'ache' with 'h' taken away is 'ACE'.
(Other definitions for ace that I've seen before include "SERVE?] that's non-returnable" , "Expert; one" , "Excellent" , "The opponent can't return this serve" , "Crack" .)