We don't have synonyms for clenching yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are bleaching, wrenching and quenching.
(n) :
The act by which something (a fist, a jaw, etc.) is clenched.
(adj) :
Alternative form of clinching (“that settles something definitely”). [That settles something (such as an argument) definitely and conclusively.]
(n) :
The act by which something (a fist, a jaw, etc.) is clenched.
(adj) :
Alternative form of clinching (“that settles something definitely”). [That settles something (such as an argument) definitely and conclusively.]