payload (n.)

c. 1200, paien, "to appease, pacify, satisfy, be to the liking of," from Old French paier "to pay, pay up" (12c., Modern French payer), from Latin pacare "to please, pacify, satisfy" (in Medieval Latin especially "satisfy a creditor"), literally "make peaceful," from pax (genitive pacis) "peace" (see peace).

The meaning "to give what is due for goods or services" arose in Medieval Latin and was attested in English by early 13c.; the sense of "please, pacify" died out in English by 1500. Figurative sense of "suffer, endure" (a punishment, etc.) is first recorded late 14c. Meaning "to give or render" with little or no sense of obligation (pay attention, pay respects, pay a compliment) is by 1580s. Meaning "be remunerative, be profitable, yield a suitable return or reward" is by 1812. Related: Paid; paying. To pay up was originally (mid-15c.) "make up the difference between two sums of money;" the sense of "pay fully or promptly" is by 1911. Pay television is attested by 1957.

c. 1200, lode, lade "that which is laid upon a person or beast, burden," a sense extension from Old English lad "a way, a course, a carrying; a street, watercourse; maintenance, support," from Proto-Germanic *laitho (source also of Old High German leita, German leite, Old Norse leið "way, road, course"), from PIE root *leit- (2) "to go forth" (see lead (v.1)).

It seems to have expanded its range of senses in early Middle English, supplanting words based on lade (v.), to which it is not etymologically connected. The older senses went with the spelling lode (q.v.). The spelling is modern. Meaning "amount customarily loaded at one time" is from c. 1300; meaning "a quantity of strong drink taken" is from 1590s. Meaning "the charge of a firearm" is from 1690s.

Meaning "a great amount or number" (often loads) is from c.1600. Figurative sense of "burden weighing on the mind, heart, or soul" is first attested 1590s. Meaning "amount (of work, etc.) to be done by one person" is attested in compounds from 1939 (first was workload). Colloquial loads "lots, heaps" is attested from c. 1600. Phrase take a load off (one's) feet "sit down, relax" is from 1914, American English. Get a load of "take a look at" is American English colloquial, attested from 1929.