Pain
Middle English (in the sense ‘suffering inflicted as punishment for an offence’): from Old French peine, from Latin poena ‘penalty’, later ‘pain’.
wiktionary
From Middle English peyne, payne, from Old French and Anglo-Norman peine, paine, from Latin poena(“punishment, pain”), from Ancient Greek ποινή(poinḗ, “bloodmoney, weregild, fine, price paid, penalty”). Compare Danish pine, Norwegian Bokmål pine, German Pein, Dutch pijn, Afrikaans pyn. See also pine (the verb). Partially displaced native Old English sār (whence English sore).
From Middle English payn(“a kind of pie with a soft crust”), from Old French pain(“bread”).
etymonline
pain (n.)
late 13c., peine, "the agony suffered by Christ;" c. 1300, "punishment," especially for a crime, "legal punishment of any sort" (including fines and monetary penalties); also "condition one feels when hurt, opposite of pleasure," including mental or emotional suffering, grief, distress; from Old French peine "difficulty, woe, suffering, punishment, Hell's torments" (11c.), from Latin poena "punishment, penalty, retribution, indemnification" (in Late Latin also "torment, hardship, suffering"), from Greek poinē "retribution, penalty, quit-money for spilled blood," from PIE *kwei- "to pay, atone, compensate" (see penal).
The early "punishment" sense in English survives in phrase on pain of death. Also c. 1300 the word was used for the torments of eternal damnation after death. The sense of "exertion, effort" is from late 14c.; pains "great care taken (for some purpose), exertion or trouble taken in doing something" is recorded from 1520s.
Phrase give (someone) a pain "be annoying and irritating" is by 1895; as a noun, localized as pain in the neck (1924) and pain in the ass (1934), though this last might have gone long unrecorded and be the original sense and the others euphemisms. First record of pain-killer "drug or herb that reduces pain" is by 1845.
pain (v.)
c. 1300, peinen, "to exert or strain oneself, strive; endeavor," from Old French pener (v.) "to hurt, cause pain," from peine, and from Middle English peine (n.); see pain (n.). Transitive meaning "cause pain; inflict pain" is from late 14c. That of "to cause sorrow, grief, or unhappiness" also is from late 14c. In Middle English also "to punish for an offense or fault; to torture, to torment." Related: Pained; paining.
