exceeding the bounds of custom, propriety, or reason, especially in amount or extent; highly excessive: to charge an exorbitant price; exorbitant luxury.
Origin: 1425–75; late Middle English < Late Latin exorbitant- (stem of exorbitāns, present participle of exorbitāre to go out of the track), equivalent to ex-ex-1 + orbit(a) wheel track (see orbit) + -ant--ant
mid-15c., from L. exorbitantem (nom. exorbitans), prp. of exorbitare "deviate, go out of the track," from ex- "out of" + orbita "wheel track." Originally "deviating from rule or principle, eccentric;" sense of "excessive, immoderate" (of prices, rates, etc.) first recorded 1660s. Related: Exorbitantly.