look up any word, like dog in the bathtub:
 
3.
figuratively spoken, the day between sunday and monday;

actually its a monday where you decide to not DO or GIVE a fuck, just like on sundays

the perfect smunday is a day, where you don't even know if it's sunday or monday
A: Are u going to school/college/work tomorrow?
B: Nah, it's smunday.

A: What day is it? Monday or Sunday? I didnt left the house today.
B: No fkin idea. Me neither.
by norbart, the pirate March 08, 2012
 
1.
Noun; The comination of the days Sunday and Monday. Often used to describe a 48 hour period of sleeplesness between Saturday and Tuesday.
"Dude, I havent sleep since yesterday, it's been one hell of a Smunday."
by KungFuCorey December 09, 2006
 
2.
When you take Monday off work because you just need an extra day off. It's not Sunday and doesn't feel like Monday, it's Smunday. Similar to how Brunch is a hybrid between Breakfast and Lunch.
I was so tired after the weekend I called into work sick this morning; I'm taking a Smunday.
by kickback chick January 20, 2012