A short nap. One that is 45 minutes or less.
Rather than saying, "Oh snap!" one should yawn, "Ooooooooooo snap-time."
Roomate #1: Man I'm exhausted.
Roomate #2: Should we take a nap before dinner?
Roomate #1: I wish. There's no time, dinner closes soon.
Roomate #2: Don't worry man, we'll take a snap!
Roomate #1: Excellent. zzzzzzzzzzzzz
Roomate #1: Do you mind if I take a nap?
Roomate #2: Make it a snap.
In order of magnitude: daydream, doze off, snap, nap, crash, sleep.