1640s, from un- (1) "not" + popular (adj.). Related: Unpopularly. Less common impopular is attested from 1721.
Entries linking to unpopular
un- 1
prefix of negation, Old English un-, from Proto-Germanic *un- (source also of Old Saxon, Old Frisian, Old High German, German un-, Gothic un-, Dutch on-), from PIE *n- (source of Sanskrit a-, an- "not," Greek a-, an-, Old Irish an-, Latin in-), combining form of PIE root *ne- "not." Often euphemistic (such as untruth for "lie").
The most prolific of English prefixes, freely and widely used in Old English, where it forms more than 1,000 compounds. It underwent a mass extinction in early Middle English, but emerged with renewed vigor 16c. to form compounds with native and imported words. It disputes with Latin-derived cognate in- (1) the right to form the negation of certain words (indigestable/undigestable, etc.), and though both might be deployed in cooperation to indicate shades of meaning (unfamous/infamous), typically they are not.
It also makes words from phrases (such as uncalled-for, c. 1600; undreamed-of, 1630s; uncome-at-able, 1690s; unputdownable, 1947, of a book; un-in-one-breath-utterable, Ben Jonson; etc., but the habit is not restricted to un-; such as put-up-able-with, 1812). As a prefix in telegramese to replace not and save the cost of a word, it is attested by 1936.
popular adj.
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]