zenithyoudaoicibaDictYouDict[zenith 词源字典]
zenith: [14] Arabic samt arrās means literally ‘path over the head’. Samt ‘path, road’ made its way via Old Spanish zenit and Old French cenit into English as zenith, bringing with it the metaphorical application to the ‘point in the sky directly overhead’. The plural of samt, sumūt, is the ultimate source of English azimuth [14].
=> azimuth[zenith etymology, zenith origin, 英语词源]
zenith (n.)youdaoicibaDictYouDict
"point of the heavens directly overhead at any place," late 14c., from Old French cenith (Modern French zénith), from Medieval Latin cenit, senit, bungled scribal transliterations of Arabic samt "road, path," abbreviation of samt ar-ras, literally "the way over the head." Letter -m- misread as -ni-.

The Medieval Latin word could as well be influenced by the rough agreement of the Arabic term with classical Latin semita "sidetrack, side path" (notion of "thing going off to the side"), from se- "apart" + *mi-ta-, suffixed zero-grade form of PIE root *mei- (1) "to change" (see mutable). Figurative sense of "highest point or state" is from c. 1600.