ellipseyoudaoicibaDictYouDict[ellipse 词源字典]
ellipse: [18] Greek élleipsis meant literally ‘defect, failure’. It was a derivative of elleípein, literally ‘leave in’, hence ‘leave behind, leave out, fall short, fail’, a compound verb formed from the prefix en- ‘in’ and leípein ‘leave’ (which is related to English loan and relinquish). It was borrowed into English in the 17th century as ellipsis in the grammatical sense ‘omission of a word or words’, but its mathematical use for an ‘oval’ (enshrined in the form ellipse, borrowed via French ellipse and Latin ellīpsis) comes from the notion that a square drawn on lines passing vertically and laterally through the centre of an ellipse ‘falls short’ of the entire length of the lateral line.
=> loan, relinquish[ellipse etymology, ellipse origin, 英语词源]
ellipse (n.)youdaoicibaDictYouDict
1753, from French ellipse (17c.), from Latin ellipsis "ellipse," also, "a falling short, deficit," from Greek elleipsis (see ellipsis). So called because the conic section of the cutting plane makes a smaller angle with the base than does the side of the cone, hence, a "falling short." The Greek word was first applied by Apollonius of Perga (3c. B.C.E.). to the curve which previously had been called the section of the acute-angled cone, but the word earlier had been technically applied to a rectangle one of whose sides coincides with a part of a given line (Euclid, VI. 27).