Philosopher isn't 'wet' gent, I fancy (12)
I believe the answer is:
wittgenstein
'philosopher' is the definition.
(Wittgenstein is an example)
'isn't wet gent i fancy' is the wordplay.
'fancy' is an anagram indicator.
'isnt'+'wet'+'gent'+'i'='isntwetgenti'
'isntwetgenti' anagrammed gives 'WITTGENSTEIN'.
(Other definitions for wittgenstein that I've seen before include "British philosopher" , "Ludwig --, Austrian-born philosopher" .)