Egg on comedian, being an utter fool (6)
I believe the answer is:
nitwit
'an utter fool' is the definition.
'nitwit' can be an answer for 'fool' (both can mean a stupid person). I am not certain of the 'an utter' bit.
'egg on comedian' is the wordplay.
'egg' becomes 'nit' (a nit is an insect egg).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'comedian' becomes 'wit' (a witty person).
'nit'+'wit'='NITWIT'
'being' is the link.
Can you help me to learn more?
(Other definitions for nitwit that I've seen before include "Birdbrain" , "Noodle, numskull" , "Foolish person like funny louse?" , "Fool, idiot" , "Louse egg with humour - silly fellow" .)