A secret phone, typically a cheap prepaid one, used in a clandestine manner away from one's SO for the sole purpose of arranging booty calls from someone other than the SO. The purpose of the bone phone is to avoid detection from the SO looking at your phone bill.
Dave: Is that Lloyd's new phone? What a loser -- why didn't he get an iPhone instead of that cheap piece of shit?

Robert: He has an iPhone...that's just his bone phone. I think he's talking to your mom
by Dick Z. Normuss July 3, 2009
When a girl has gauged earlobes big enough to fit your cock into. Then you insert your penis from the backside so that the tip sits right next to her mouth, resembling a phone. Then she can suck or lick the tip like she is talking on the phone.
Check out that chick with the gauged earrings, I bet she nobs on the bone phone!
by Bummybumkin December 24, 2016
When someone has your cock near their mouth you call it your "Bone Phone" and they are answering it for you.
While your down their can you answer my Bone Phone, it's calling.
by CableBob September 6, 2008
A slang term for a man's penis, frequently used in a sexual or humorous context and particularly favored by musicians.
Sarah can't play guitar worth shit but she's quite a virtuoso on the ol' bone a phone.
by hnoss April 6, 2017
Another name for a cock,dick.
As in,she's talking on my bone a phone.

Hey Bitch ! Don't you hear that ringing sound between my legs?
It's my bone a phone and it's ringing for you.

She talked on my bone a phone, all night long.
by NoLove_4_BS April 21, 2009