(noun) Someone who loves anal sex so much, they'll bend over for any willing dick, regardless of circumstances. These people are also frequently dubbed asswhores, anal-whores, and politicians.
"Jon is such a buttramp! I saw him bent over, grabbing his ankles, and taking the captain of the football team's meat sword in his ass."
"Christa is a buttramp! The Owner fired her and the Department Manager when he caught them having anal sex in the officeyesterday during lunch!"
A mobile phone call placed accidentally and unintentionally, usually from the Send button getting pushed during normal movement while the phone is in your back pocket (next to your butt).
"My phone rang about five timesin a row and there was nobody there. Each one was a buttcall from Tricia!"