fortminute Share definition Flag A fortminute is a measure of time dervived from the use of fortnight. A fortminute is roughly fifteen regular minutes. Sir, could I pardon you for the time? Of course lad. It's a fortminute till 5. Righto! fortminute by Neffizzle July 11, 2009 0 0 Get merch Get the fortminute mug. Buy Now — $32.95 See more merch