The tattoo a stoned, depressed, college-aged kid gets when he decides to take his/her life. Commonly found on an easily spotted place on the body like the face or neck.
On the same premise as TGI Friday, the term stands for "Fuck My Life it's Monday." This term is appropriate for any given Monday where in which someone feels that their life has been completely and utterly fucked. For most people, all Mondays seem appropriate.