英语词源字典 - 在线词源网站

east [east 词源字典]: Old English east, eastan (adj., adv.) "east, easterly, eastward;" easte (n.), from Proto-Germanic *aust- "east," literally "toward the sunrise" (cognates: Old Frisian ast "east," aster "eastward," Dutch oost Old Saxon ost, Old High German ostan, German Ost, Old Norse austr "from the east"), from PIE *aus- (1) "to shine," especially of the dawn (cognates: Sanskrit ushas "dawn;" Greek aurion "morning;" Old Irish usah, Lithuanian auszra "dawn;" Latin aurora "dawn," auster "south;" see aurora). The east is the direction in which dawn breaks. For theory of shift in the geographical sense in Latin, see Australia.

As one of the four cardinal points of the compass, from c. 1200. Meaning "the eastern part of the world" (from Europe) is from c. 1300. Cold War use of East for "communist states" first recorded 1951. French est, Spanish este are borrowings from Middle English, originally nautical. The east wind in Biblical Palestine was scorching and destructive (as in Ezek. xvii:10); in New England it is bleak, wet, unhealthful. East End of London so called by 1846; East Side of Manhattan so called from 1871; East Indies (India and Southeast Asia) so called 1590s to distinguish them from the West Indies.[east etymology, east origin, 英语词源]
Sirius (n.): brightest star by magnitude, late 14c., from Latin Sirius "the Dog Star," from Greek Seirios, said to mean literally "scorching" or "the scorcher." But other related Greek words seem to derive from this use, and the name might be a folk-etymologized borrowing from some other language. An Egyptian name for it was Sothis. The connection of the star with scorching heat is from its ancient heliacal rising at the summer solstice (see dog days). Also see dog star. Related: Sirian. The constellation Canis Major seems to have grown from the star, not the other way.
Homer made much of it as [Kyon], but his Dog doubtless was limited to the star Sirius, as among the ancients generally till, at some unknown date, the constellation was formed as we have it, -- indeed till long afterwards, for we find many allusions to the Dog in which we are uncertain whether the constellation or its lucida is referred to. [Richard Hinckley Allen, Canis Major in "Star Names and Their Meanings," London: 1899]
torrid (adj.): 1580s, in torrid zone "region of the earth between the tropics," from Medieval Latin torrida zona, from fem. of torridus "dried with heat, scorching hot," from torrere "to parch," from PIE root *ters- "to dry" (see terrain). Sense of "very hot" is first attested 1610s. Figurative sense from 1630s.