Bump
mid 16th century (as a verb): imitative, perhaps of Scandinavian origin.
wiktionary
From Early Modern English bump(“a shock, blow from a collision", also "to make a heavy, hollow sound, boom”), probably of North Germanic origin. Compare Danish bump(“a thump”), Danish bumpe(“to thump”), Old Danish bumpe(“to strike with a clenched fist”). Apparently related to Middle English bumben, bummen(“to make a hollow noise”), Dutch bommen(“to hum, buzz”), German bummen(“to hum, buzz”), Icelandic bumba(“drum”), probably of imitative origin. More at bum, bumble. Compare also bomb.
etymonline
bump (n.)
1590s, "protuberance caused by a blow;" 1610s as "a dull-sounding, solid blow;" see bump (v.). The dancer's bump and grind attested from 1940. To be like a bump on a log "silent, stupidly inarticulate" is by 1863, American English.
bump (v.)
1560s, "to bulge out;" 1610s, "to strike heavily, cause to come into violent contact," perhaps from Scandinavian, probably echoic, if the original sense was "hitting" then of "swelling from being hit." It also has a long association with the obsolete verb bum "make a booming noise." To bump into "meet by chance" is from 1886; to bump off "kill" is by 1908 in underworld slang. Related: Bumped; bumping. Bumpsy (adj.) was old slang for "drunk" (1610s).
