See snap or oh snap.
When using prediction text (or t9), when one types in "snap", it spells the word as "soap" instead. But "oh soap" sounds lame.
Thus! A "n" is added, fusing the two words making an entirely new awesome word.
In math class:
Teacher: we're going to be learning how to do the same exact problems we've been doing...except with negatives.
Student: Oh snoap!
Teacher: WTF, mate?
Student: Excuse me?!?! I'm SO telling the principal about your foul mouth!
Teacher: oh snoap.