Green’s Dictionary of Slang

1. the penis.

1568		R. Sempill ‘Flemyng Bark’ Ballates 231: In moneless nichtis it is na mowis, Except ane stowt man steir hir ruder.
1611		Davies of Hereford Vpon Eng. Prouerbes II 46: Ill goes the boate without the ore / And without rudder ill the whoore.
c.1624		T. Carew A Rapture (1927) 8: My Rudder, with thy bold hand [...] thou shalt steer and guide [...] into Love’s channell, where it shall Dance.
[1675		W. Lawrence Diary July 24: It is this little Member, which, like the Rudder of a Ship, steeres the mind as well of the prince as the peasant. ’Tis a Remora that can stop a Ship in its full saile].
1707		Humours of a Coffee-House 10 Oct. 34: I am sorry to see him so very much out of Order. I with Love’s Dragon, that often lurks in the Garden of Venus, has bit him by the Rudder of his Affections.
1709		N. Ward Rambling Fuddle-Caps 3: As for the Rudders that steer our Affections [...] Were know grown as stiff as a Bullock’s Defender.
a.1749		Robertson of Struan ‘Marriage Song’ Poems (1752) 95: Sure Venus never can be tir’d / While pow’ful Mars directs the Rudder.
c.1800		Burns ‘Cupid’s Frolic’ in Merry Muses of Caledonia (1843) 44: Love’s rudder, Cupid steering, To harbour ’tween her thighs.
1856		Life in Boston & N.Y. (Boston, MA) 23 Aug. n.p.: Try and put out the fire, or, ere you know it, the whole vessel will be consumed, rudder and all — and everybody knows what a poor thing a vessel is without a rudder to steer her.
1890–1904		Farmer & Henley Sl. and Its Analogues.

2. an animal’s tail, usu. a dog’s.

1984

Partridge DSUE (8th edn) 995/1: joc. C.20.