Fisticuffs is old-fashioned fighting with bare hands. Two men, no weapons, coats off and handed to a friend.
Nobody uses the word seriously any more, and that is rather the point of it: fisticuffs is now almost entirely jocular, the word you reach for when a squabble in a car park is being described as though it were a duel. It is plural in form and takes a plural verb, and it usually appears inside a set frame — it came to fisticuffs, they resorted to fisticuffs. The parts still show through, since a cuff is a blow with an open hand.
1nounfisticuffsFighting with the fists, especially treated as comically old-fashioned.
“The argument very nearly ended in fisticuffs.”