Former partner joining group making comeback gets praise (5)
I believe the answer is:
extol
'praise' is the definition.
(extolling is a kind of praising)
'former partner joining group making comeback' is the wordplay.
'former partner' becomes 'ex'.
'joining' means one lot of letters go next to another.
'group' becomes 'lot' (lot is a kind of group**).
'making comeback' is a reversal indicator.
'lot' reversed gives 'tol'.
'ex'+'tol'='EXTOL'
'gets' acts as a link.
(Other definitions for extol that I've seen before include "Speak well of" , "Glorify - honour" , "'Praise, glorify (5)'" , "Say great things about" , "Highly rate" .)