Irritate husband in restaurant (5)
I believe the answer is:
chafe
'irritate' is the definition.
(I've seen this before)
'husband in restaurant' is the wordplay.
'husband' becomes 'h'.
'in' means one lot of letters goes inside another.
'restaurant' becomes 'cafe' (cafe is a kind of restaurant**).
'h' placed within 'cafe' is 'CHAFE'.
(Other definitions for chafe that I've seen before include "feel irritated" , "Wear away by rubbing" , "Become sore by rubbing" , "Abrade" , "Rub painfully" .)