popularize v.

early 15c., populer, "public, commonly known," from Old French populaire and directly from Latin popularis "belonging to the people, general, common; devoted to or accepted by the people; democratic," from populus "people" (see people (n.)).

Meaning "of or pertaining to the people; depending on the people," especially the common people, is from 1540s. Meaning "suited to ordinary people, easily comprehended" is from 1570s in English; hence, of prices, "low, affordable to average persons" (1859).

The meaning "well-liked, admired by or enjoying the favor of the people" is attested from c. 1600. Of art, entertainment, etc., "favored by people generally" from 1819 (popular song). Related: Popularly. Popular Front "coalition of Communists, Socialists, and radicals" is from 1936, first in a French context.

Popular sovereignty, in U. S. hist., the theory that the right to decide whether slavery should exist in a territory rested with the people of that territory, and not with Congress. It was advocated especially by Democrats during the period 1847-61, and its leading champion was Douglas. It was often termed "squatter sovereignty," with which it was nearly identical. [Century Dictionary]

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.