- between
[between 词源字典] - between: [OE] The second syllable of between is related to two and twin; the word as a whole seems to represent an original phrase meaning something like ‘by two each’. Old English betwēonum reflects a Germanic *twēon, reduced from an earlier *twikhnai; this represents the base *twīkh- (from which we get two) plus an -n suffix with apparently some sort of distributive function. The related betwixt comes ultimately from Germanic *twa ‘two’ and the element *-isk- ‘-ish’.
=> twin, two[between etymology, between origin, 英语词源] - between (prep.)
- Old English betweonum "between, among, by turns," Mercian betwinum, from bi- "by" (see be-) + tweonum dative plural of *tweon "two each" (compare Gothic tweih-nai "two each"). Between a rock and a hard place is from 1940s, originally cowboy slang. Between-whiles is from 1670s.
