Green’s Dictionary of Slang

1. a watchman, a constable.

1700

T. Brown Amusements Serious and Comical in Works (1744) III 22: The man-eaters, that stood not far off, seeking whom they might devour [...] I have been too lately in their clutches to desire any more dealings with them.

2. a swindler.

1833		Ely’s Hawk & Buzzard (NY) Sept. 14 n.p.: There now resides in our good city [...] one of the bold man-eaters [...] alias, Doctor Quick [...] he swears that if any of his bad deeds are exposed [...] he will bung the two eyes of poor Johannas .
1926		Wood & Goddard Dict. Amer. Sl. 46: shark. an expert; also a gouger, man-eater, as in loan-shark.

3. (Anglo-Ind.) a horse that tends to bite people.

1838		Sporting Mag. Nov. 31 : The larger horses from Hindoostan [...] are leggy, under-limbed, and, as far as vice goes, regular man-eaters .
1884		Civil & Milit. Gaz. (Lahore) 19 June 1/3: Girofle, while being trained last year [...] developed a most violent temper, and came to be universally regarded as a ‘man-eater’.
1919		Van Loan ‘Chivalry in Carbon County’ in Score by Innings (2004) 320: They ain’t none of ’em what you might call man-eaters, but they’re feerocious enough for New Jersey.

4. a sexually predatory woman.

1890		Dead Bird (Sydney) 27 Sept. 6/3: A dandy crowd of genuine sports, [...] mashers and man-eaters rubbing shoulders in all directions.
1906		E. Dyson Fact’ry ’Ands 136: To Spats’ Beauties she was always Porline or The Man-Eater.
1919		‘Bartimeus’ ‘The Wooing of Mouldy Jakes’ in Awfully Big Adventure 38: I’m not going to face those man-eaters alone.
1926		J. Black You Can’t Win (2000) 54: Wha do you think she did, kid — the big man-eater!
1963		B. Hecht Gaily, Gaily 92: I’ve always wanted to love one of those creamy-skinned man-eaters.
1975		C. Dexter Last Bus to Woodstock 179: Mary indeed! Dumpy, freckled, little man-eater!
1988		(con. 1940s) C. Bram Hold Tight (1990) 187: You afraid bad man-eating Lena’s gonna throw herself at you.
1999		Guardian G2 22 July 11: As if Lulu was an aggressive man-eater.
2005		J. Stahl I, Fatty 52: Lilly-Bell, a big blond [sic] maneater.

5. a tough overseer, employer, etc.

1925		N. Lucas Autobiog. of a Thief 201: The chief officer [...] was a ‘man-eater,’ they said, and hated stowaways.
1931		B. Lubbock Bully Hayes 59: It took a hell of a man-eater to tackle Bully Hayes.

6. a homosexual man; a fellator.

1972		B. Rodgers Queens’ Vernacular 52: fellator [...] maneater.
1979		Maledicta III:2 231: A sod or a bugger need not be a pedicator any more than a cocksucker in America need be a maneater, a head artist, a flute-player or a fellator.
1988		H. Max Gay (S)language 27: Maneater—gay who performs fellatio often and/or well.