[bump] n [prob. imit. of the sound of a blow] (1592) 1: a relatively abrupt convexity or protuberance on a surface: as a: a swelling of tissue b: a cranial protuberance
2. a: a sudden forceful blow, impact, or jolt b: demotion
3: an act of thrusting the hips forward in an erotic manner
[2]bump vt (1611) 1: to strike or knock with force or violence
2: to collide with 3 a (1): to dislodge with a jolt (2): to subject to a scalar change "rates being ~ed up" b: to oust usu. by virtue of seniority or priority "was ~ed from the flight" ~ vi 1: to knock against something with a forceful jolt
2: to proceed in or as if in a series of bumps
3: to encounter something that is an obstacle or hindrance "~ed up against a chair" -- bump into : to encounter esp. by chance