Pirate caught wife (4)
I believe the answer is:
crib
'pirate' is the definition.
(I've seen this before)
'caught wife' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'wife' becomes 'rib'.
'c'+'rib'='CRIB'
(Other definitions for crib that I've seen before include "Child's bed - copy" , "Student's aid; bed" , "Steal - key - child's bed" , "Cheat by copying - card game" , "Container for animal fodder" .)