iron curtain n.

Middle English iron, iren, yron, from Old English iren, variant (with rhotacism of -s-) of isen, later form of isern, isærn "the metal iron; an iron weapon or instrument," from Proto-Germanic *isarn (source also of Old Saxon isarn, Old Frisian isern, Old Norse isarn, Middle Dutch iser, Old High German isarn, German Eisen).

This perhaps is an early borrowing of Celtic *isarnon (compare Old Irish iarn, Welsh haiarn), which Watkins suggests is from PIE *is-(e)ro- "powerful, holy," from PIE *eis "strong" (source also of Sanskrit isirah "vigorous, strong," Greek ieros "strong"), on the notion of "holy metal" or "strong metal" (in contrast to softer bronze).

Both an adjective and a noun in Old English, but in form an adjective. The alternative isen survived into early Middle English as izen. In southern England the Middle English word tended to be ire, yre, with loss of -n, perhaps regarded as an inflection; in the north and Scotland, however, the word tended to be contracted to irn, yrn, still detectable in dialect.

Right so as whil that Iren is hoot men sholden smyte. [Chaucer, c. 1386]

Chemical symbol Fe is from the Latin word for the metal, ferrum (see ferro-).

The meaning "metal device used to press or smooth clothes" is from 1610s. The meaning "golf club with an iron head" is by 1842. To have (too) many irons in the fire "to be doing too much at once" is from 1540s. Iron lung "artificial respiration tank" is from 1932. The iron crown was that of the ancient kings of Lombardy, with a thin band of iron in the gold, said to have been forged from a nail of Christ's Cross.

Iron horse "railroad locomotive" is from an 1839 poem. Iron maiden, instrument of torture, is from 1837 (probably translating German eiserne jungfrau). The unidentified French political prisoner known as the man in the iron mask died in the Bastille in 1703. In British history, Wellington was called the Iron Duke by 1832.

c. 1300, curtine, "hanging screen of textile fabric used to close an opening or shut out light, enclose a bed, or decorate an altar," from Old French cortine "curtain, tapestry, drape, blanket," from Late Latin cortina "curtain," but in classical Latin "round vessel, cauldron," from Latin cortem (older cohortem) "enclosure, courtyard" (see cohort).

The meaning shift apparently begins with cortina being used as a loan-translation of Greek aulaia ("curtain") in the Vulgate (to render Hebrew yeriah in Exodus xxvi:1, etc.). The Greek word was connected to aule "court," perhaps because the "door" that led out to the courtyard of a Greek house was a hung cloth.

Figuratively from early 15c. as "something that conceals or screens." From 1590s as "large sheet used to conceal the stage in a theater." Many of the figurative senses are from stage plays: Behind the curtain "concealed" is from 1670s; curtains "the end" is by 1912. The theatrical curtain call "appearance of individual performers on stage at the end of a performance to be recognized by the audience" is from 1884. To draw the curtain is from c. 1500 in opposite senses: "to conceal," and "to reveal." Curtain-rod is from c. 1500. An Old English word for "curtain" was fleonet "fly-net."

type of giant grass common in the tropics, 1590s, from Dutch bamboe and/or Portuguese bambu, earlier mambu (16c.), probably from Malay (Austronesian) samambu, though some suspect this is itself an imported word, perhaps from Kanarese (Dravidian). Bamboo curtain in reference to communist China (based on iron curtain) is from 1949.