Green’s Dictionary of Slang

1. worthless.

1851		Life in Boston & N.Y. (Boston, MA) 4 Jan. n.p.: He was once seen [...] to march off with his bob-tail company, followed only by a big troop of darkies.
1872		E. Perkins Saratoga in 1901 207: The masters of this bob-tail vernacular [i.e. ‘society’ slang].
[1879		Nat. Police Gaz. (NY) 22 Nov. 15/3: A man loses his ducats upon a ‘dead heat’ or a ‘bob-tail flush’].
1897		Kansas City Jrnl (MO) 16 May 13/4: Morrissey and Scovel. One with two Jacks and the Other with a Bobtail Flush.
1900		P.G. McLean ‘A Long Shot’ Variety Stage Eng. Plays 🌐 miss b: What were you called last? jack: On a bob-tail flush.
1901		Bulletin (Sydney) 10 Aug. 12/4: [T]he members of the Lower House were the untidiest, hungriest-looking lot you could see anywhere. Judge Darley is a grand-seigneur, but the majority of the men at the show were unspeakably bob-tail.
1907		C. M’Govern By Bolo and Krag 199: They was betting fifty beans on a lousy bob-tailed flush.
1916		O.O. McIntyre New York Day by Day 4 Apr. [synd. col.] Trying to fill a bobtail flush under the impression you were gambling.
1936		(con. 1830s–60s) ‘Miles Franklin’ All That Swagger 185: Mrs Urquart was free to enjoy Bella and to wonder why she had thrown herself away on bob-tailed old James.
1972		(con. 1916) G. Swarthout Tin Lizzie Troop (1978) 167: He stared at the bobtail bunch of boys in partial uniform before him.
1994		J. Wambaugh Finnegan’s Week 143: The bobtail van belonging to Green Earth Hauling and Disposal had not been in the stolen vehicle system for long.

2. of a garment short; of a name/word abbreviated.

1907		H. Champion ‘That Funny Little Bob-Tailed Coat’ [monologue] You do look a guy, you’re a proper old pie, / In that funny little bob-tailed coat .
1950		A.B. Guthrie Way West 19: ‘Name’s Hig,’ the figure announced. ‘Or that’s what they call me. It’s bobtail for Higgins.’.