One judges sliced rarebit (7)
I believe the answer is:
arbiter
'one judges sliced rarebit' is the definition.
I can't judge whether this defines the answer.
'sliced rarebit' is the wordplay.
'sliced' is an anagram indicator.
'rarebit' anagrammed gives 'ARBITER'.
Can you help me to learn more?
(Other definitions for arbiter that I've seen before include "One must exercise judgment" , "One who settles disputes" , "Judge, final authority" , "Judge, adjudicator" , "Judge, umpire" .)