Tough participant in the Manx Grand Prix (2-3)
I believe the answer is:
he-man
'tough' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe you can see a link between them that I can't see?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for he-man that I've seen before include "Macho type" , "Alpha male" , "Tough guy, doubly male" , "Muscular fellow" , "Extremely virile male" .)