Monday-to-Friday Share definition Flag A euphemism for mother-f***ing. Recently seen in the televised version of Snakes on a Plane. Samuel L. Jackson: I have had it with these monkey-fighting snakes on this Monday-to-Friday plane! (Cocks gun.) Monday-to-Friday by MrSmartyPants April 26, 2009 0 0 Get merch Get the Monday-to-Friday mug. Buy Now — $32.95 See more merch