Marry husband, having a constant desire (5)
I believe the answer is:
hitch
'marry' is the definition.
(I've seen this before)
'husband having a constant desire' is the wordplay.
'husband' becomes 'h'.
'having' says to put letters next to each other.
'a constant desire' becomes 'itch' (I've seen this in another clue).
'h'+'itch'='HITCH'
(Other definitions for hitch that I've seen before include "Yank" , "unite" , "Make fast" , "couple" , "Temporary problem" .)