sineyoudaoicibaDictYouDict[sine 词源字典]
sine: [16] As in the case of many other mathematical terms, English is indebted to Arabic for sine. But here the debt is only semantic, not formal. The word sine itself was borrowed from Latin sinus ‘curve, fold, hollow’ (source also of English sinuous [16] and indeed of sinus [16], whose anatomical use comes from the notion of a ‘hollow’ place or cavity). In postclassical times it came to denote the ‘fold of a garment’, and so it was mistakenly used to translate Arabic jayb ‘chord of an arc’, a doppelganger of Arabic jayb ‘fold of a garment’.
=> sinuous, sinus[sine etymology, sine origin, 英语词源]
sine (n.)youdaoicibaDictYouDict
trigonometric function, 1590s (in Thomas Fale's "Horologiographia, the Art of Dialling"), from Latin sinus "fold in a garment, bend, curve, bosom" (see sinus). Used mid-12c. by Gherardo of Cremona in Medieval Latin translation of Arabic geometrical text to render Arabic jiba "chord of an arc, sine" (from Sanskrit jya "bowstring"), which he confused with jaib "bundle, bosom, fold in a garment."