Highly regarded old partner rang (8)
I believe the answer is:
extolled
'highly regarded' is the definition.
Although both the answer and definition are past participle verbs, I can't see how they can define each other.
'old partner rang' is the wordplay.
'old partner' becomes 'ex' (an ex-partner).
'rang' becomes 'tolled' (tolling is a kind of ringing).
'ex'+'tolled'='EXTOLLED'
Can you help me to learn more?
(Other definitions for extolled that I've seen before include "Praised and glorified" , "Praised highly, lauded" , "Exalted" , "magnified" , "Sang the praises of" .)