1640s, "one who schemes or plots;" agent noun from design (v.). In manufacturing or the fine arts, "one who makes an artistic design or a construction plan" is from 1660s. In fashion, as an adjective, "bearing the label of a famous clothing designer" (thus presumed to be expensive or prestigious), from 1966. Designer drug, one that mimics an illegal narcotic but has a different chemical composition so as to avoid legal restrictions, is attested by 1983.

late 15c., from Latin interior "inner, interior, middle," comparative adjective of inter "within" (from PIE *enter "between, among," comparative of root *en "in"). Specific meaning "away from the coast, of the interior parts of a country" is from 1777. Interior decoration first attested 1769; interior decorator is from 1830. Interior design from 1927.

"part of a country distant from the coast," 1796, from interior (adj.); meaning "internal part, inside" is from 1828. Meaning "internal affairs of a country or state" (as in U.S. Department of the Interior) is from 1826. The Latin adjective also was used as a noun.

1701, from interior + -ity.

"interior regions" of a land, 1560s, from in (prep.) + country.

"within the hull or interior of a ship," 1830, from in (adv.) + board (n.2).

"interior regions," 1680s, from up- + country (n.). As an adjective from 1810; as an adverb from 1864.

descriptive of a dress or skirt flared in shape of a capital letter "A," 1955, in reference to the creations of French fashion designer Christian Dior (1905-1957).

capital of Oman, from Arabic Masqat, said to mean "hidden" (it is isolated from the interior by hills).

"upholsterer's work, furniture covered with textile materials, interior fittings made from textiles," 1640s; see upholster + -y (4).