Henry longed to get married (7)
I believe the answer is:
hitched
'married' is the definition.
(I've seen this before)
'henry longed' is the wordplay.
'henry' becomes 'h' ('H' can be a synonym of 'henry').
'longed' becomes 'itched' (I've seen this before).
'h'+'itched'='HITCHED'
'to get' acts as a link.
(Other definitions for hitched that I've seen before include "Sought lift using thumb signal" , "Not a single" , "Hooked to a vehicle" , "Thumbed a lift" , "married" .)