ETYMOLOGY
from clunch (to clench) + fist
EXAMPLE
“…such a quoile with pro and con, such vrging of Ergoes, til they haue gone fro Art togither by the eares, and made their conclusions end with a Clunchfist, right like the old description of Logicke…”
From: Plaine Percevall, the Peace-maker of England:
Being a Reply to Martin Mar-Prelate
By Richard Harvey, 1590
Lexicophilia 