expression, noun which may take the genitive case particle 'no'
locked in a grapple; grappling fiercely; struggling together
Describes two or more people physically wrestling or locked in a close struggle, often with the nuance of a chaotic, back-and-forth tussle. Used as a set phrase, typically with の or in adverbial form くんずほぐれつして.
二人はくんずほぐれつの大乱闘を繰り広げた。
The two of them got into a fierce, grappling brawl.
酔っ払いたちがくんずほぐれつしながら路上で騒いでいた。
The drunkards were making a racket on the street, wrestling and tumbling around.
取っ組み合い is a noun meaning a scuffle or fistfight, often implying a more serious physical fight. くんずほぐれつ emphasizes the chaotic, entangled nature of the struggle and is more literary or set-phrase-like.
格闘 is a general term for hand-to-hand combat or grappling, used in sports and serious contexts. くんずほぐれつ is a vivid, colloquial expression for a messy, close-quarters tussle.
A compound of 組んず (くんず, an old or dialectal form of 組む meaning 'to grapple') and 解れつ (ほぐれつ, from 解れる meaning 'to come untied' or 'to unravel'), with the つ ending giving a classical or emphatic feel. The phrase literally suggests 'grappling and unraveling', evoking a back-and-forth struggle. The exact historical derivation is uncertain, but it is a fixed idiomatic expression.