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. 1300, paie, "satisfaction, liking; reward, reprisal," from pay (v.), or else from Old French paie "payment, recompense," from paier. Meaning "money or other compensation given for labor or services performed, wages" is from late 14c. In Middle English the usual sense was "satisfaction": My pay meant "my liking;" God's pay was "God's good will."
"a payer, one who pays," by 1817, agent noun in Latin form from pay (v.). Chiefly legalese.
late 14c., "person who pays," originally wages, later taxes (early 15c.), from Old French paiere (13c.), agent noun from paier (see pay (v.)).