A slang term used in various forms to describe something as terrible. Commonly used as a derogatory remark against someone when they're being highly tedious and/or annoying.
Guy 1: "Oh man, this Sex On The Beach is so tasty and the umbrella really compliments my hair colour"
Guy 2: "Dude, you're so blaith right now, it hurts."
Guy 2: "Dude, you're so blaith right now, it hurts."
by Reagansmash1994 November 27, 2012
Get the Blaithmug. to hang out and do nothing, this may or may not include a nap, and may or may not include an ice cold natty.
by The Blaithmeister December 16, 2009
Get the blaithmug.