aboutyoudaoicibaDictYouDict[about 词源字典]
about: [OE] About in Old English times meant ‘around the outside of’; it did not develop its commonest present-day meaning, ‘concerning’, until the 13th century. In its earliest incarnation it was onbūtan, a compound made up of on and būtan ‘outside’ (this is the same word as modern English but, which was itself originally a compound, formed from the ancestors of by and out – so broken down into its ultimate constituents, about is on by out).
=> but, by, out[about etymology, about origin, 英语词源]
about (adv.)youdaoicibaDictYouDict
Old English abutan, earlier onbutan "on the outside of," from on (see on; also see a- (1)) + be "by" (see by) + utan "outside," from ut (see out (adv.)). By 13c. it had forced out Old English ymbe, ymbutan for meaning "in the neighborhood of." Abouts, with adverbial genitive, still found in hereabouts, etc., probably is a northern dialectal form. About face as a military command (short for right about face) is first attested 1861, American English.