1) The act of putting off assignments, generally large projects for homework, until late Sunday night. Average finish time for sundaynighting is approximately 2-3 am, though all nighters are quite common.

2) Extreme procrastination

Other forms: sundaynight - ing

Abbr: sunnighting, sunighting
1) "Have you finished that atmosphere project yet?"

"Nah, I'm gonna sundaynight it."

2) "Dude!! Stop sundaynighting and get working on that African history essay!"
by nallina March 4, 2009