late 15c. (Caxton), "austerity or strictness of life," from French severite, from Latin severitatem (nominative severitas) "seriousness, strictness, sternness," a derivative of severus "stern, strict, serious" (see severe). The meaning "strictness in dealing with others" is recorded from 1520s. OED marks severeness (1570s) as "rare."
It forms all or part of: Antioch; asseverate; asthenia; asthenosphere; cachectic; cachexia; calisthenics; cathexis; entelechy; eunuch; epoch; hectic; Hector; ischemia; myasthenia; neurasthenia; Ophiuchus; persevere; schema; schematic; scheme; scholar; scholastic; school (n.1) "place of instruction;" severe; severity; Siegfried.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit sahate "he masters, overcomes," sahah "power, victory;" Avestan hazah "power, victory;" Greek skhema "figure, appearance, the nature of a thing," related to skhein "to get," ekhein "to have, hold; be in a given state or condition;" Gothic sigis, Old High German sigu, Old Norse sigr, Old English sige "victory."
"one who exercises undue severity in the use of power or authority," c. 1400, oppressour, from Old French opresseor, from Latin oppressor "a crusher, a destroyer," from opprimere (see oppress (v.)). In Middle English also "a criminal; a rapist" (mid-15c.).
1540s, "quality of being sharp or pungent in taste," from French acrimonie or directly from Latin acrimonia "sharpness, pungency of taste," figuratively "acrimony, severity, energy," abstract noun from acer "sharp" (fem. acris), from PIE root *ak- "be sharp, rise (out) to a point, pierce") + -monia suffix of action, state, condition. Figurative extension to personal sharpness or bitterness is by 1610s.
