anxiety (n.) Look up anxiety at Dictionary.com
1520s, "apprehension caused by danger, misfortune, or error, uneasiness of mind respecting some uncertainty," from Latin anxietatem (nominative anxietas) "anguish, anxiety, solicitude," noun of quality from anxius "uneasy, troubled in mind" (see anxious).

Sometimes considered a pathological condition (1660s); psychiatric use dates to 1904. Age of Anxiety is from Auden's poem (1947). For "anxiety, distress," Old English had angsumnes, Middle English anxumnesse.