Green’s Dictionary of Slang

1. a telephone.

2001		G. Coughlan Everyday Eng. and Sl. 🌐 hambone: phone.
2002		B. Kirkpatrick Wicked Cockney Rhy. Sl. 35: ham and bone [...] telephone.
2011		J.J. Connolly Viva La Madness 218: I explain, when I see you, not on the hambone.

2. (US) a trombone.

1934

Weseen Dict. Amer. Sl. 167: Hambone—A trombone.