Merriam-Webster's Collegiate® Dictionary, 11th Edition
HUMP
I. noun
Etymology: akin to Middle Low German hump bump, Dutch homp lump, chunk, Frisian homp, himp
Date: 1681
a rounded protuberance: as, humpback 1, a fleshy protuberance on the back of an animal (as a camel, bison, or whale), c. mound , hummock , mountain , range , a fit of depression or sulking, a difficult, trying, or critical phase or obstacle, humped adjective
II. verb
Date: circa 1785
transitive verb to copulate with, to exert (oneself) vigorously, to make humpbacked ; hunch , to put or carry on the back ; lug , intransitive verb to exert oneself ; hustle , to move swiftly ; race