When one is as big as a thumb. Often known as a mark or 2 inches. Often caused by looking at attracktive girls. Like AD or AH.
by Crippler8 February 28, 2008
Get the Thumbaleenamug. Get the Thumbaleenamug. Get the Thumbaleenamug. Get the Thumbaleenamug. We'll email you a link to sign in instantly.