Green’s Dictionary of Slang

1. (also lobby gob) a hanger-on, a messenger, a servant, an errand boy, esp. one who frequents or works in an opium den or brothel, or a tourist guide in Chinatown.

1899		Nat. Police Gaz. (NY) 25 Mar. 3: Shut that door, lobby gow .
1906		I. Swift Sketches of Gotham 41: The lobbygows – the errand men of the Chinese – the whites, who execute commissions for them [etc.].
1908		Sun (NY) 22 May 2/3: The strike of lobbygows [...] put all Chinatown askew [...] Ginger, leader of the strikers [...] immediately called all the striking lobs together.
1913		A.B. Reeve Constance Dunlap 295: He’s a lobbygow for the grapevine system they have now of selling the dope in spite of this new law.
1915		S. Ford Torchy, Private Sec. 21: Just because I’m behind the ground glass [...] don’t make me a sacred being, or you a lobbygow.
1927		H. Asbury Gangs of N.Y. 316: These dives [...] were also the headquarters of the white parasites who had drifted into Chinatown and earned precarious livings as Lobbygows, or guides to the quarter.
1932		L.E. Lawes Twenty Thousand Years in Sing Sing 323: When he was in the section where the other men were confined, he would be the ‘fall guy’ or ‘lobby gob’ for them.
1947		L.J. Valentine Night Stick 51: Even [Dutch] Schultz’s lobbygows and errand boys managed to dress better than the boss.
1949		Monteleone Criminal Sl. (rev. edn) 147: lob [...] lobby gon [sic] A loafer in an opium den.
1956		‘Toney Betts’ Across the Board 177: He flung away fortunes in grubstakes to bums, heels and lobby-gows.
1959		J.E. Schmidt Narcotics Lingo and Lore 100: Lob – One who hangs around opium smoking dens, doing menials for the operators and, more so, for those operated on, by the pipe. Lobby gow – An opium den loafer.

2. a Chinese police informer.

1909

C.B. Chrysler White Slavery 78: They [the Chinamen] bury them in one of the many underground graves, where they bury the informer, or ‘lobbygow’. [Ibid.] 80: The girl had not been in the den more than twenty-four hours before a ‘lobbygow’ – a Chinaman who acts as stool pigeon and informer to the police – told two Mulberry Street detectives.

3. in fig. use, an insignificant person.

1913		T.A. Dorgan Silk Hat Harry’s Divorce Suit 12 Feb. [synd. cartoon strip] You peanut headed roustabout, you false alarm lobby gow.
1929		S. Ornitz Haunch Paunch and Jowl 142: Stay where youse are, youse guzzlers and lobbygows, youse lousey tripe, don’t move.
1991		in J. Breslin Damon Runyon (1992) 260: Runyon [...] listened to another lobbygow gush.

4. a ruffian, a low-class thief.

1908		D.G. Phillips Susan Lenox II 190: One of those terrors of tenement women, the lobbygows — men who live by lying in wait in the darkness to seize and rob the lonely, friendless woman.
1911		G. Bronson-Howard Enemy to Society 295: I ain’t gunna have her think Stevey’s tied up with a bunch of lobby-gows.