Green’s Dictionary of Slang

1. an act of sexual intercourse [bob v.² (1)].

1590		Sidney Arcadia II (1912) 203: A foolish thing with fooles to deal: Let him be bold that bobs will have; But who by means of wisdom hie Hath sav’d his charge? – It is even I.
1654		Mercurius Fumigosus 14 30 Aug.–6 Sept. 120: But first they will give you a bobb, a bobb, / and then they will give you a blow, / And when you have knock’d them once above, / they’l tickle your pockets below.
1704		Comical Observator 2 7–14 Nov. n.p.: [She will be] preserving her Life by a Saluriferous Bob or two.
c.1720		‘Perkin in a Cole-Sack’ in Farmer Merry Songs and Ballads (1897) V 171: And Ruth in Bed could in her turn, / Tho’ modest of Behaviour; / With all her Heart a Bob have born, / Had she not fear’d a Feaver.
1772		Bridges Burlesque Homer (3rd edn) 268: I stay’d to do a little job, In which she always bears a bob.

2. the penis.

1798		‘Gentleman’s Wig’ in Hilaria 86: In went his dry bob, his wet bob, and all.
1834		‘The Country Girl & Her Little Bob’ in Randy Songster in Spedding & Watt (eds) I 193: To cool her heated wishes, he / Soon gave her little Bob.
1836		‘The Way to Come Over a Maid’ in New Cockalorum Songster in Spedding & Watt (eds) Bawdy Songbooks (2011) II 26: Next just feel her thigh, / Then a little higher! / If she won’t wince at that, / Put Bob in her grasp then.

3. (US prison) an effeminate male homosexual [abbr. bend over backwards].

2002

J. Lerner You Got Nothing Coming 179: ‘Yo, Bob, come to Daddy! Your daddy’s been waiting on you!’ Back in the world, ‘Bob’ is the nickname for ‘Robert.’ In here it’s an acronym for ‘bend over backwards’.