What is the meaning of Billy?

A billy club.

A billy goat.

  1. (Can we clean up this sense?) A male goat; a ram.

(Can we clean up this sense?) A male goat; a ram.

A good friend.

A condom.

A slubbing or roving machine.

A silk handkerchief.

A tin with a swing handle used to boil tea over an open fire; a billycan; a billypot.

A bong for smoking marijuana.

Source: wiktionary.org