patronize (v.)

c. 1300, patroun, "a lord-master, one who protects, supports, or encourages," also "one who has the right of presenting a clergyman to a preferment," from Old French patron "patron, protector, patron saint" (12c.) and directly from Medieval Latin patronus "patron saint, bestower of a benefice; lord, master; model, pattern, example," from Latin patronus "defender, protector; former master (of a freed slave); advocate," from pater (genitive patris) "father" (see father (n.)). A doublet of pattern (n.); also compare patroon.

From late 14c. as "founder of a religious order," also "a patron saint." The meaning "one who advances and encourages the cause or work" of an artist, institution, etc., usually by means of the person's wealth and power, is suggested from late 14c., clearly in this sense by c. 1600; "commonly a wretch who supports with insolence, and is paid with flattery" [Johnson]. The commercial sense of "regular customer" is recorded from c. 1600. Patron saint "saint regarded as a special protector of a person, place, profession, etc." (by 1717) originally was simply patron (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.