exorcise v.

early 15c., "a calling up or driving out of evil spirits," from Late Latin exorcismus, from Greek exorkismos "administration of an oath," in Ecclesiastical Greek, "exorcism," from exorkizein "exorcise, bind by oath," from ex "out of" (see ex-) + horkizein "cause to swear," from horkos "oath," which is of uncertain origin. Some linguists propose a connection with herkos "fence," "in which case it would properly denote the oath as the bounds that one assumes, a restriction, tie, or obligation" or "a magical power that fences in the swearer" [Beekes], but this is not accepted by all. Earlier in the same sense was exorcization (late 14c.).

word-forming element used to make verbs, Middle English -isen, from Old French -iser/-izer, from Late Latin -izare, from Greek -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached.

The variation of -ize and -ise began in Old French and Middle English, perhaps aided by a few words (such as surprise, see below) where the ending is French or Latin, not Greek. With the classical revival, English partially reverted to the correct Greek -z- spelling from late 16c. But the 1694 edition of the authoritative French Academy dictionary standardized the spellings as -s-, which influenced English.

In Britain, despite the opposition to it (at least formerly) of OED, Encyclopaedia Britannica, the Times of London, and Fowler, -ise remains dominant. Fowler thinks this is to avoid the difficulty of remembering the short list of common words not from Greek which must be spelled with an -s- (such as advertise, devise, surprise). American English has always favored -ize. The spelling variation involves about 200 English verbs.

mid-14c., "condition of being in active operation; practice for the sake of training," from Old French exercice (13c.) "exercise, execution of power; physical or spiritual exercise," from Latin exercitium "training, physical exercise" (of soldiers, horsemen, etc.); "play;" in Medieval Latin also of arts, from exercitare, frequentative of exercere "keep busy, keep at work, oversee, engage busily; train, exercise; practice, follow; carry into effect; disturb, disquiet," from ex "off" (see ex-) + arcere "keep away, prevent; contain, enclose," from PIE *ark- "to hold, contain, guard" (see arcane).

The original notion in the Latin verb is obscure. Meaning "physical activity for fitness, etc." first recorded in English late 14c. Also from late 14c. as "a carrying out of an action; a doing or practicing; a disciplinary task." In reference to written schoolwork from early 17c. The ending was abstracted for formations such as dancercise (1967); jazzercise (1977); and boxercise (1985).