A headache as a result of smoking low-grade marijuana (schwag).
"Man, I smoked a blunt of that schwag this morning and it gave me a schwag-ache afterwards.. I really need some dank."
by Duke of Devonshire November 27, 2007
The headache induced by smoking or ingesting inexpensive, low-quality marijuana.
"Ugh, Shannon buys such shitty pot. I always have a schwagache when I leave her place."
by Meredyth September 06, 2006