Recognised leader in some field (4)

I believe the answer is:

guru

'recognised leader in some field' is the definition.
(I've seen this before)

This is the entire clue.

(Other definitions for guru that I've seen before include "Master, mentor" , "Revered mentor" , "Authoritative source" , "Religious leader and spiritual teacher" , "Recognised leader in some field" .)

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app