Criterion for judging fool on stage (10)
I believe the answer is:
touchstone
'criterion' is the definition.
(synonyms)
'for judging fool on stage' is the wordplay.
I cannot quite understand how this works, but
'for' could be 'to' (eg both can mean 'in the opinion of') and 'to' is located in the answer.
'on' could be 'to' and 'to' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for touchstone that I've seen before include "Shakespearean character" , "Character in As You Like It" , "Jasper" , "Standard" , "forest-dweller" .)
