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.
1520s, "apprehension caused by danger, misfortune, or error, uneasiness of mind respecting some uncertainty, a restless dread of some evil," from Latin anxietatem (nominative anxietas) "anguish, anxiety, solicitude," noun of quality from anxius "uneasy, troubled in mind" (see anxious).
It was sometimes considered a pathological condition (1660s); modern psychiatric use dates to 1904. Age of Anxiety is from Auden's poem (1947). For "anxiety, distress," Old English had angsumnes, Middle English anxumnesse.
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.
early 15c., "diligence, industry, activity; anxiety, care, concern," from Old French solicitude (Modern French sollicitude), and directly from Latin sollicitudinem (nominative solicitudo) "anxiety, uneasiness of mind," noun of state from past-participle stem of solicitare (see solicit).
1620s, "greatly troubled by uncertainties," from Latin anxius "solicitous, uneasy, troubled in mind" (also "causing anxiety, troublesome"), from angere, anguere "to choke, squeeze," figuratively "to torment, cause distress" (from PIE root *angh- "tight, painfully constricted, painful").
The same image is in Serbo-Croatian tjeskoba "anxiety," literally "tightness, narrowness." The meaning "earnestly desirous" (as in anxious to please) is from 1742. Related: Anxiously; anxiousness.