Praise no longer key? (5)
I believe the answer is:
exalt
'praise' is the definition.
(exalting is a kind of praising)
'no longer key?' is the wordplay.
'no longer' becomes 'ex'.
'key?' becomes 'alt' (I've seen this in other clues**).
'ex'+'alt'='EXALT'
(Other definitions for exalt that I've seen before include "(P) raise" , "Raise in praise" , "Praise - latex (anag)" , "put on a pedestal" , "Laud" .)