Green’s Dictionary of Slang

1. (Irish) the penis.

c.1785

‘The Coughing Old Man’ in A. Carpenter Verse in Eng. in 18C Ireland (1998) 395: But to my sad vexation and consternation, / His hautboy was feeble and weak in the main.

2. (US) a nightsoil carrier.

1820		N.-Y. Eve. Post 7 June 2/3: The carelessness and insufferable conduct of our black night-gentry; commonly called Hobey-men.
1842		Whip & Satirist of NY & Brooklyn (NY) 19 Mar. n.p.: Name: BV Profession: Ho-boy.
1845		Subterranean (N.Y.) 28 June 2/3: People can not be too cautious how they even touch sausages – even when made properly [...] but as they are now made, by hoeboys, and out of putrid dogs and rats, they are truly horrifying. The sale of them ought to be interdicted by law.
1877		Bartlett Dict. Americanisms (4th edn) 288: Ho-boy, or Haut boy. A nightman. New York.
1889		Farmer Americanisms 299: Ho-boy or haut boy.—A New York night scavenger.
1947		(con. 1860s) F. Weitenkampf Manhattan Kaleidoscope 20: Into the duties of the men called ‘ho-boys,’ who had to carry malodorous substance from backyards to carts on the street, we hardly need go.