in medicine, "exhaustion from lack of nourishment," c. 1400, "pathological draining or depletion of blood, humors, or bodily fluids," from Old French inanition (14c.) and directly from Latin inanitionem (nominative inanitio) "emptiness," noun of action from past-participle stem of inanire "to empty," from inanis "empty, void; worthless, useless," a word of uncertain origin.
1580s, from Greek elephantos, genitive of elephas "elephant" (see elephant) + -iasis "pathological or morbid condition." It refers to two diseases, one characterized by thickening of a body part (E. Arabum), the other, older meaning is "disease characterized by skin resembling an elephant's" (E. Græcorum, also called Egyptian leprosy). In Middle English, elephancy (late 14c.).
late 14c., "endowed with the power of growth," from Old French vegetatif "(naturally) growing," from Medieval Latin vegetativus, from vegetat-, past participle stem of vegetare (see vegetable (adj.)). Middle English transferred sense was "characterized by growth." Modern pathological sense of "brain-dead, lacking intellectual activity, mentally inert" is from 1893, via notion of having only such functions which perform involuntarily or unconsciously and thus are likened to the processes of vegetable growth.
early 14c., "discomfort, inconvenience, distress, trouble," from Old French desaise "lack, want; discomfort, distress; trouble, misfortune; disease, sickness," from des- "without, away" (see dis-) + aise "ease" (see ease (n.)). Restricted pathological sense of "sickness, illness" in English emerged by late 14c.; the word still sometimes was used in its literal sense early 17c., and was somewhat revived 20c., usually with a hyphen (dis-ease).
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.
1610s (implied in dissociated) "sever the association or connection of," especially "cut off from society," from Latin dissociatus, past participle of dissociare "to separate from companionship, disunite, set at variance," from dis- "apart" (see dis-) + sociare "to join," from socius "companion, ally," from PIE *sokw-yo-, suffixed form of root *sekw- (1) "to follow."
Attested from 1540s as a past-participle adjective meaning "separated." Dissociated in psychology (1890) was "characterized by mental disjunction," hence dissociated personality (1905) "pathological state in which two or more distinct personalities exist in the same person."