barber: n. a patron, usually intoxicated, who participates in every song. From "The Barber of Seville."
flipper: n . a singer who flips his hair to and fro with every verse.
kariography: n. karaoke choreography. "The singing stunk but the kariography would make even Liza Minnelli hang up her shoes."
KMIA: Karaoke Missing in Action. A performer who signed up to sing but is nowhere in sight.
newser: n. a greenhorn who sings a regular's signature song. "That newser just shredded my song."
phantom: n. a patron who unexpectedly joins a singer on a tune.
powersong: n. a popular, crowd-pleasing song. "She's a shoo-in to win the contest with that Tina Turner powersong backing her up."
shadow: v. when one singer stands behind another but can't muster the gumption to actually sing.
shred: v. to destroy a song.
software: n. a person who sings so softly the audience hears only the background music.