Wife upset pet and broke down (4)
I believe the answer is:
wept
'broke down' is the definition.
(I've seen this in another clue)
'wife upset pet' is the wordplay.
'wife' becomes 'w' (abbreviation).
'upset' indicates anagramming the letters.
'pet' is an anagram of 'ept'.
'w'+'ept'='WEPT'
'and' acts as a link.
(Other definitions for wept that I've seen before include "Sobbed heavily" , "lamented" , "Cried, sobbed" , "Was unhappy" , ""Jesus __" (shortest verse in the King James Bible)" .)