Green’s Dictionary of Slang

bobtail n.1

[pun on SE bobtail, a horse or dog with its tail cut short ]

1. an unpleasant person, thus a thug [a cur].

[UK]Fletcher Monsieur Thomas (1639) II ii: I’le not be bob’d i’ th’ nose with every bobtail .
[UK]J. Phillips Maronides (1678) VI 98: Which grim Judge hearing sends his bob-tails / To comb his tawnie skin with Hob-nails.

2. an impotent man, a eunuch.

[UK]Man in the Moon 4 26 Nov. 28: Kittermaster (alias quite Whore-master) [whose] shortness is caused by the long continuance of his wenching, no wonder then if he be call’d Bob, to which if you add Tale it will better discover his Trade into the Antipodes.
[UK]New Canting Dict. n.p.: bob-tail [...] also an Eunuch or impotent Fellow.
[UK]Bailey Universal Etym. Eng. Dict. [as cit. 1725].
[UK]Grose Classical Dict. of the Vulgar Tongue.
[UK]Lex. Balatronicum.

3. a prostitute; thus bobtailed adj. [cf. SE bob, go up and down + tail n. (2); a horse is also good for a ride n. (1a)].

[UK]T. Killigrew Thomaso Pt II III ii: I hate such hawking at the Bush with those Bobtails; Give me a long-wing’d Hawke, a high flying whore, ’tis sport to see her stoop.
[UK]J. Wade Vinegar and Mustard B: Do you remember how thou layst with a Fisher-man for a quardern of Mackarel, and when you came back agen how you paid the Water-man with a pox that carried you, thou bobtail’d Whore thou.
[UK]B.E. Dict. Canting Crew n.p.: Bob-tail, a light Woman.
[UK]New Canting Dict.
[UK]Bailey Universal Etym. Eng. Dict. [as cit. 1725].
[UK]Sterne Tristram Shandy (1949) 334: There was a good farcical house, large enough to hold – aye – and sublimate them, shag-rag and bob-tail, male and female, all together.
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: Bob tail, (cant) a lewd woman, or one that plays with her tail.
[UK] ‘The Bob-Tail’d Lass’ in Farmer Merry Songs and Ballads (1897) I 276: I was never so disgraced in my life / As I was by this bob-tail’d whoore.
[UK]Lex. Balatronicum.
[UK]‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc.
[UK]G. Kent Modern Flash Dict.
[UK]Flash Dict. in Sinks of London Laid Open.
[UK]Duncombe New and Improved Flash Dict.
[UK]J. Meades Empty Wigs (t/s) 209: The pretty popsy bobtail must have agreed without much hesitation to their offer.