Wise words supporting cleric elevated by bishop (7)
I believe the answer is:
proverb
'wise words' is the definition.
(a wise saying)
'supporting cleric elevated by bishop' is the wordplay.
'supporting' becomes 'pro' (being pro something is supporting it).
'cleric' becomes 'Rev' (abbreviation for Reverend).
'elevated' says the letters should be written in reverse (in a down clue, letters go up).
'by' is a charade indicator (letters next to each other).
'bishop' becomes 'B' (chess abbreviation).
'rev' written backwards gives 'ver'.
'pro'+'ver'+'b'='PROVERB'
(Other definitions for proverb that I've seen before include "OT saying" , "Short saying embodying a supposed truth" , "encapsulate wisdom" , "Make haste slowly, perhaps" , "Saying of great truth" .)