Source of wisdom (6)
I believe the answer is:
oracle
'source of wisdom' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for oracle that I've seen before include "One believed to give divinely-inspired answers" , "Holy place in ancient times where gods prophesied" , "Diviner of the future" , "Holy place where a god was believed to give advice and prophecy" , "Soothsayer" .)