Zenith comes from Old French cenith, from Medieval Latin senit, a corrupt reading of Arabic سَمْت (samt, 'path, direction'), from the phrase samt ar-raʼs ('path over the head'). In current use it is a noun meaning "the highest point reached; the point in the sky directly overhead". That sense is explained by the older material without requiring a speculative semantic step: the inherited or borrowed base supplies the field of meaning, while the English formation fixes its modern role. The history is mainly one of transmission into English, with the older form and sense carried through borrowing or adaptation. The historical chain includes Old French cenith and Arabic سَمْت. A derived form is zenithal. For dictionary purposes, the important point is the continuity between the older form, the route into English, and the present lexical sense.