This is the term for fucking, or going deep into som-one, this originated from a European boy who proclaimed "I am The Plunger! and i shall Plunge Thee"
Mr.Man: "Oh man your so gonna get plunged, im gonna plunge you so hard you won't be able to sit down for a week"
when you make fun of someone or trick someone so badly they have nothing else to say back. note: being deca-punked is much worse than just the normal everyday punked.
roommate #1: your chicken pad thai is here!
roommate #2: fuck, it's about time.
roommate #1: sike!!!! you just got deca-punked.