1853 in the literal sense (witch-hunting is from 1630s), from witch (n.) + hunt (n.). The extended sense is attested from 1919, American English, later re-popularized in reaction to Cold War anti-Communism.
Senator [Lee S.] Overman. What do you mean by witch hunt?
Mr. [Raymond] Robins. I mean this, Senator. You are familiar with the old witch-hunt attitude, that when people get frightened at things and see bogies, then they get out witch proclamations, and mob action and all kinds of hysteria takes place. ["Bolshevik Propaganda," U.S. Senate subcommittee hearings, 1919]
"Chinese cuisine prepared as bite-sized portions served in small steamer baskets or on small plates," 1948, from Cantonese tim sam (Chinese dianxin) "appetizer," said to mean literally "touch the heart." Ayto ("Diner's Dictionary") gives the elements as tim "dot" + sam "heart."
"nuclear, biological and chemical weapons" attested by 1946, apparently first used (in Russian) by the Soviets.
The terms "weapons of mass destruction" and "WMD" mean chemical, biological, and nuclear weapons, and chemical, biological, and nuclear materials used in the manufacture of such weapons. [United States Code: Title 50, "War and National Defense," chapter 43, § 2902, 2009]
1902, from French, literally "free verse," lines of varying length.
I remarked some years ago, in speaking of vers libre, that 'no vers is libre for the man who wants to do a good job.' The term, which fifty years ago had an exact meaning in relation to the French alexandrine, now means too much to mean anything at all. [T.S. Eliot, introduction to "Selected Poems of Ezra Pound," 1928]
name borne by two rulers of Tenochtitlan in ancient Mesoamerica, from Spanish Moctezuma, from Nahuatl (Aztecan) Moteuczoma, said to mean "he who frowns like a lord" or "he who is angry in a noble manner." Montezuma's revenge, "severe intestinal infection" sometimes suffered by non-natives in Mexico, is by 1962, in reference to Montezuma II (1466-1520), Aztec ruler at the time of the Spanish arrival and conquest of Mexico.
Chinese dish of stir-fried noodles served with sauce, 1898, American English, from Chinese ch'ao mien, said to mean "fried dough."
Whereas the majority of Chinese culinary terms in English have become established since the Second World War, with the rise of the Chinese restaurant, chow mein belongs to an earlier stratum, introduced via the West Coast of America in the early years of the twentieth century, and institutionalized in the 1920s and 1930s as the archetypal Sino-American dish. [Ayto, "Diner's Dictionary"]
c. 1600, "part of the Italian mainland ruled by Venice," from Modern Latin terra firma, literally "firm land," from Latin terra "earth, land" (from PIE root *ters- "to dry") + firma, fem. of firmus "strong, steadfast" (from suffixed form of PIE root *dher- "to hold firmly, support"). Meaning "the land" (as distinct from "the sea") is first attested 1690s. Hakluyt and Sandys also used English firm (n.) to mean "the firm land, the mainland, terra firma."