Subprudentiaism Share definition Flag Word for someone without a mental deficiency who is so indescribably dumb you have to use a new word to get your point across. “Hey I think that’s Jeffery over there.” “Oh doesn’t he have subprudentiaism?” “The fuck?” Subprudentiaism by Thegamingplum August 11, 2020 Get the Subprudentiaism mug.