Sweatache Share definition Flag When you haven't showered for days and you smell so bad of old sweat that you get a headache. Kyle: Dude, you smell awful! Ethan: Yeah! it's so bad it's giving me a sweatache.. Sweatache by inzolin October 26, 2010 0 0 Get merch Get the Sweatache mug. Buy Now — $32.95 See more merch