A person, mainly females, who sucks a lot of dick and gets cumm all over their face. This happens happens to them them a lot making them "rusted", therefore bringing the name rusted cum-bucket.
David: "Damn I heard that girl over there has been jizzed on hella times."
Ludin: "I know shes a real rusted cum-bucket!"
The Rusted Trombone: When a man receives a rim job and a reach around (aka a handjob where the recipient, is in the front) at the same time and then proceeds to rip ass while getting the rimmy reach around combo.
Rusted Trombone Player, "There are 3 reasons why I like to play rusted trombones, the feel, the taste, and the smell."