Former partner ringing - praising ... (9)
I believe the answer is:
extolling
'praising' is the definition.
(extolling is a kind of praising)
'former partner ringing' is the wordplay.
'former partner' becomes 'ex' (an ex-partner).
'ringing' becomes 'tolling' (tolling is a kind of ringing).
'ex'+'tolling'='EXTOLLING'
(Other definitions for extolling that I've seen before include "Lauding, glorifying" , "Praising" , "taking part in Lauds?" , "Applauding" , "Cracking up" .)