Put out, former wife can spout about one (10)
I believe the answer is:
extinguish
'put out' is the definition.
('extinguish' can be a synonym of 'put out')
'former wife can spout about one' is the wordplay.
'former wife' becomes 'ex'.
'can' becomes 'tin' ('tin' can be a synonym of 'can').
'spout' becomes 'gush' ('gush' can be a synonym of 'spout').
'about' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'gush' enclosing 'i' is 'guish'.
'ex'+'tin'+'guish'='EXTINGUISH'
(Other definitions for extinguish that I've seen before include "Put out (a light/fire)" , "Stop" , "Quench" .)