1776, "functional derangement arising from disorders of the nervous system (not caused by a lesion or injury)," coined by Scottish physician William Cullen (1710-1790) from Greek neuron "nerve" (see neuro-) + Modern Latin -osis "abnormal condition." Originally of epilepsy, hysteria, neuralgia, etc. Used in a general psychological sense from 1871, "change in the nerve cells of the brain resulting in symptoms of stress," but not radical loss of touch with reality (psychosis); clinical use in psychiatry dates from 1923.
1560s, "to fight, struggle, contend" (intransitive), from French combat (16c.), from Old French combattre (12c.), from Late Latin combattere, from Latin com "with (each other)," see com-, + battuere "to beat, fight" (see batter (v.)). Transitive sense is from 1580s; figurative sense from 1620s. Related: Combated; combating; combatted; combatting.
1560s, "a fight," originally especially "a fight between two armed persons" (later distinguished as single combat, 1620s), also in a general sense of "any struggle or fight between opposing forces," from French combat (see combat (v.)).
1757, French, literally "out of combat." Hors (prep.) "out, beyond," is from Latin foris (adv.) "outside," literally "out of doors" (see foreign). De is from Latin de "of." For combat see combat (n.). A similar expression from French is hors concours "out of competition" (1884), of a work of art in an exhibition.
1775, "acting upon or stimulating the nerves," from Greek neuron "nerve" (see neuro-) + -otic, as in hypnotic. Also compare neurosis. Meaning "relating to the nervous system" is by 1873. Sense of "affected by or prone to neurosis" is by 1887. The noun meaning "a neurotic person" is from 1896; earlier it meant "a drug acting on the nerves" (1660s). Related: Neurotically.
late 15c., duelle (from late 13c. in Latin form), "a single combat," also "a judicial single combat," from Medieval Latin duellum "combat between two persons," from Latin duellum "war," an Old Latin form of bellum (see bellicose). The Old Latin word was retained in poetic and archaic language and apparently given a special meaning in Medieval or Late Latin of "one-on-one combat" on fancied connection with duo "two."
Sometimes also in Italian form duello. The English word by 1610s had taken on the specialized sense of "premeditated and pre-arranged single combat involving deadly weapons in the presence of at least two witnesses." General sense of "any contest between two parties" is from 1590s.
"engage in single combat, fight a duel," 1640s, see duel (n.). Related: Dueled; dueling; duelling.