Upset husband interrupting public spat (9)
I believe the answer is:
overthrow
'upset' is the definition.
(synonyms)
'husband interrupting public spat' is the wordplay.
'husband' becomes 'h' (abbreviation).
'interrupting' means one lot of letters goes inside another.
'public' becomes 'overt' (both can mean well-known or unconcealed).
'spat' becomes 'row' (I've seen this in another clue).
'overt'+'row'='overtrow'
'h' inserted within 'overtrow' is 'OVERTHROW'.
(Other definitions for overthrow that I've seen before include "caused discomfiture" , "Error on cricket field - defeat" , "Trevor who? (anag)" , "Dethrone or oust" , "depose government" .)