muscleman, n. — Green’s Dictionary of Slang

muscleman n.

[note Hughes, Tom Brown at Oxford (1861): ‘I must call the persons in question “musclemen,” as distinguished from muscular Christians’; his ref. is to those who celebrate physical strength but have no religious faith; note 1945 Minnesota Univ. use muscle moll, a strong man]

(orig. US)

1. a thug, usu. as employed by a gangster for purposes of intimidation; any strong, aggressive man.

1927		Appleton Post-Crescent (WI) 25 Apr. 1/5: A ‘muscle man’ is one of a band of criminals who has taken to the kidnapping, extortion and robbery of persons who are themselves engaged in some illicit enterprise.
1931		J. Wilstach Under Cover Man 92: His two remaining henchmen, ‘Fry’ Patten and Pete Kely, muscle men, not thinkers.
1946		Mezzrow & Wolfe Really the Blues 21: I got my kicks out of rubbing elbows with all those bigtime gamblers and muscle men.
1955		B. Schulberg On the Waterfront (1964) 136: Johnny Friendly’s pair of muscle men hard-shouldered their way over to [...] another group.
1962		S. Longstreet Flesh Peddlers (1964) 336: One of the musclemen who watched the cashier’s window came over.
1966		J. Holledge Great Aust. Gamble 149: So Slater gained confidence and, enlisting a few reliable ‘muscle men’, set up his own gang.
1970		‘Red’ Rudensky Gonif 79: He [...] had been everything from a hijacker to a muscle-man.
1989		B. Raveendran Saints and Sinners 25: One of the labourers had refused to give on his pay-day a heavy subscription to his muscleman labour leader for which he was knocked down and thrashed.

2. (also muscle freak) a man with an outstanding physique.

1877		U. Michigan Chronicle VIII 268: Then a muscleman approached me, / M Jerry, give the rest a slashing. / But, remember, if you hit me. / You will get a deuced thrashing.
1934		Weseen Dict. Amer. Sl. 261: [Sports – Misc.] Muscleman – A wrestler.
1942		Berrey & Van den Bark Amer. Thes. Sl.
1955		‘Ed Lacy’ Best that Ever Did It (1957) 29: ‘This Franklin Andersun, was he a muscleman?’ Danny laughed [...] ‘Couldn’t lift a toothpick.’.
1961		F. Kohner Gidget Goes Hawaiian 77: The first thing that loomed into view when I arrived at Al Mona was a group of bronzed musclemen.
1984		W. Diehl Hooligans (2003) 42: He’s also a muscle freak.
2007		K. LePage Some Day Never Comes 119: I was at the gym a few months ago, and right next to me was a huge muscleman pumping iron.