Someone who sings along inappropriately loudly and overzealously to songs, often effectively disturbing the atmosphere and ruining the song.
Our friend Liza is a huge oversinger. She doesn't get it when she is belting out songs in the car at the TOP OF HER LUNGS and everyone thinks its totally awkward.
A shirt overbite occurs when someone is really fat and has a huge stomach. The bottom of their shirt is the same vertical length as the top of their pants but there is a huge horizontal gap between them because their shirt is hanging from their belly. There is a horizontal gap between the end of the shirt and the beginning of the pants, due to their huge protruding belly.
Eli is so fat that when he tries to pick up girls they take one look at his six inch shirt overbite, laugh, and turn around. Eli tries to hide his shirt overbite by wearing long shirts.
Having an overboner is getting overexcited or stressed about a fairly trivial event. i.e takingsomething too seriously.
Edward Law (at lunchtime soccer): Come on guys, we're losing, COME ON!
Rob dodds: Meh
Ed: NO, we need to start playing, you're all so shit
Everyone else in unison: SHUT UP ED, don't get an overboner!