pizzle

A pizzle is the penis of an animal, especially a bull.

The word is old-fashioned and appears mainly in two contexts: dried bull pizzles sold as dog chews, and as a mild historical insult.

Shakespeare used it: What said Master Dombledon about the satin for my short cloak and my slops?

He said, sir, you should procure him better assurance than Bardolph: he would not take his band and yours; he liked not the security.

Let him be damned, like the glutton! Pray God his tongue be hotter! A whoreson Achitophel! A rascally yea-forsooth knave! To bear a gentleman in hand, and then stand upon security! The whoreson smooth-pates do now wear nothing but high shoes, and bunches of keys at their girdles; and if a man is through with them in honest taking-up, then they must stand upon security. I had as lief they would put ratsbane in my mouth as offer to stop it with security. I looked a' should have sent me two and twenty yards of satin, as I am a true knight, and he sends me security. Well, he may sleep in security; for he hath the horn of abundance, and the lightness of his wife shines through it: and yet cannot he see, though he have his own lanthorn to light him. Where's Bardolph?

He's gone into Smithfield to buy your worship a horse.

I bought him in Paul's, and he'll buy me a horse in Smithfield: an I could get me but a wife in the stews, I were manned, horsed, and wived.

Actually, a simpler example: Falstaff calls someone a bull's pizzle as an ins