also north-west, Old English norþwest (adv.) "to a point or in a direction between north and west;"  from north + west. As a noun, "region or locality lying in the northwest of a country," and adjective from late 14c.

In U.S. geography it was at first, the territory that later became Ohio, Indiana, Illinois, Wisconsin, Michigan and northeastern Minnesota (1787); after about 1853 the term was applied to the unorganized territory north of Nebraska, west of Minnesota, and east of the Rockies. Pacific Northwest, describing Oregon and Washington, is by 1874. Related: Northwestern; northwesterly; northwestward (late 14c.).

Northwest Passage as the name of an at-first hypothetical sea route from the Atlantic to the Pacific by the northern coasts of North America, first attested c. 1600. The Northwest Ordinance (1787) was an act of Congress to organize the territory beyond the Appalachian Mountains between the Great Lakes and the Ohio River.

also westernise, 1837, originally in reference to the U.S. West, from western + -ize.

Emigrants from Europe have brought the peculiarities of the nations and countries from whence they have originated, but are fast losing their national manners and feelings, and, to use a provincial term, will soon become "westernized." [J.M. Peck, "A New Guide for Emigrants to the West," Boston, 1837]

In reference to Europeanizing of Middle Eastern or Asian places and persons, from 1867. Related: Westernized; westernizing.

West African type of loose shirt, 1969, a word of West African origin.

vegetable cultivated in the East and West Indies and southern U.S., 1670s, from a West African language (compare Akan nkruma "okra").