Is not participating in ring toss, unusually, finding it very intense (6)
I believe the answer is:
strong
'intense' is the definition.
(similar in meaning)
'is not participating in ring toss unusually' is the wordplay.
'not participating in' suggests deleting specific letters.
'unusually' indicates an anagram.
'ring'+'toss'='ringtoss'
'ringtoss' with 'is' taken out is 'rngtos'.
'rngtos' anagrammed gives 'STRONG'.
'finding it very' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for strong that I've seen before include "Able to withstand attack" , "Decisive - spicy - bright - tough" , "Convincing" , "Physically powerful - feel 1 Across" , "Powerful; full-flavoured" .)