hump: [18] Hump seems to have originated among the Low German dialects of North Germany and the Low Countries – Dutch, for instance, has the probably related homp ‘lump’. It first appeared in English towards the end of the 17th century in the compound hump-backed, but by the first decade of the 18th century it was being used on its own. (Another theory is that it arose from a blend of the now obsolete crumpbacked with hunchbacked [16], whose hunch- is of unknown origin.)
hump (n.)
1680s (in hump-backed), from Dutch homp "lump," from Middle Low German hump "bump," from Proto-Germanic *hump-, from PIE *kemb- "to bend, turn, change, exchange." Replaced, or perhaps influenced by, crump, from Old English crump. A meaning attested from 1901 is "mound in a railway yard over which cars must be pushed," which may be behind the figurative sense of "critical point of an undertaking" (1914). Humpback whale is from 1725.
hump (v.)
"to do the sex act with," attested from 1785, but the source of this indicates it is an older word. Meaning "to raise into a hump" is from 1840. Related: Humped; humping.
