word-forming element, in English meaning usually "out of, from," but also "upwards, completely, deprive of, without," and "former;" from Latin ex "out of, from within; from which time, since; according to; in regard to," from PIE *eghs "out" (source also of Gaulish ex-, Old Irish ess-, Old Church Slavonic izu, Russian iz). In some cases also from Greek cognate ex, ek. PIE *eghs had comparative form *eks-tero and superlative *eks-t(e)r-emo-. Often reduced to e- before -b-, -d-, -g-, consonantal -i-, -l-, -m-, -n-, -v- (as in elude, emerge, evaporate, etc.).

"hidden, secret," 1540s, from Latin arcanus "secret, hidden, private, concealed," from arcere "to close up, enclose, contain," from arca "chest, box, place for safe-keeping," from PIE root *ark- "to hold, contain, guard" (source also of Greek arkos "defense," arkein "to ward off;" Armenian argel "obstacle;" Lithuanian raktas "key," rakinti "to shut, lock").

"dancing as exercise," 1967, from dance (n.) + ending from exercise (n.).

c. 1400, "to invoke spirits," from Old French exorciser (14c.), from Late Latin exorcizare, from Greek exorkizein "banish an evil spirit; bind by oath" (see exorcism). Sense of "call up evil spirits to drive them out" became dominant 16c. Formerly also exorcize; a rare case where -ise trumps -ize on both sides of the Atlantic, perhaps due to influence of exercise. Related: Exorcised; exorcising.

1977, originally a proprietary name, from jazz (n.) + ending from exercise (n.).