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.
romantic adj.
1650s, "of the nature of a literary romance, partaking of the heroic or marvelous," from French romantique "pertaining to romance," from romant "a romance," an oblique case or variant of Old French romanz "verse narrative" (see romance (n.)).
Of places, "characterized by poetic or inspiring scenery," by 1705. As a literary style, opposed to classical (q.v.) since before 1812; it was used of schools of poetry in Germany (late 18c.) and later France. In music, "characterized by expression of feeling more than formal methods of composition," from 1885. Meaning "characteristic of an ideal love affair" (such as usually formed the subject of literary romances) is from 1660s. Meaning "having a love affair as a theme" is from 1960. Related: Romantical (1670s); romantically; romanticality. Compare romanticism.