Bump  —n. 1 dull-sounding blow or collision. 2 swelling or dent so caused. 3 uneven patch on a road etc. 4 prominence on the skull thought to indicate a mental faculty. —v. 1 a hit or come against with a bump. B (often foll. By against, into) collide. 2 (often foll. By against, on) hurt or damage by striking (bumped my head, the car). 3 (usu. Foll. By along) move along with jolts. —adv. With a bump; suddenly; violently.  bump into colloq. Meet by chance. Bump off slang murder. Bump up colloq. Increase (prices etc.).  bumpy adj. (-ier, -iest). [imitative]