stoner clause Share definition Flag every year on 4/19 Stoner Clause travels to young stoner's homes and fills they're empty altoids tins with weed, ready for when they wake up on 4/20 "Mommy, how come Stoner Clause always gives me less weed then he gives Johnny?" stoner clause by Muffn Queen September 11, 2004 Get the stoner clause mug.