An acronym for Thank God It's Not Monday. Similar to TGIF, but with a wider period of use. TGINM is often used when someone gets that special TGIF feeling when it isn't actually Friday.
Peter is a sick man on the first day of every week. But when he isn't down with a case of the Mondays, he is TGINM'ing.
by Will Car-painter May 27, 2007