Austin Powers' father (5)
I believe the answer is:
nigel
'austin powers' father' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nigel that I've seen before include "One knighted by Conan Doyle," , "Man's name" , "First name of the leader of the Brexit Party since 2019" , "We all sign on (anag) -- politician" , "-- Gresley, railway engineer" .)