Wanderlust of tetchy wife heading off travelling (5,4)
I believe the answer is:
itchy feet
'wanderlust' is the definition.
(I know that wanderlust can be written as itchy feet)
'tetchy wife heading off travelling' is the wordplay.
'heading off' means to remove the first letter.
'travelling' indicates an anagram.
'wife' with its first letter taken away is 'ife'.
'tetchy'+'ife'='tetchyife'
'tetchyife' is an anagram of 'ITCHY FEET'.
'of' is the link.
(Other definitions for itchy feet that I've seen before include "Strong desire to travel" , "Those with these have a strong impulse to travel" , "Restlessness, a desire to travel - or scratch?" , "reason for leaving?" , "Have . . . . . . . . . with restless desire to travel" .)