'hump' originates from Middle English, from forms such as 'humpen' or 'hump', probably of imitative origin referring to a swelling or protuberance.

'hump' changed from Middle English forms like 'humpen' and related variants and developed into the modern English word 'hump' with both noun and verb senses.

Initially it meant 'a swelling or protuberance'; over time it broadened to the verb sense 'to form into a hump' and figurative senses (a difficulty to overcome) and informal/slang senses (sexual meaning).