Rude  adj. 1 impolite or offensive. 2 roughly made or done; crude (rude plough). 3 primitive or uneducated (rude simplicity). 4 abrupt, sudden, startling (rude awakening). 5 colloq. Indecent, lewd (rude joke). 6 vigorous or hearty (rude health).  rudely adv. Rudeness n. [latin rudis]