ETYM Old Eng. senyth, Old Fren. cenith, French zénith, Spanish zenit, cenit, abbrev. from Arabic samt-urras way of the head, vertical place; samt way, path + al the + ras head. Related to Azimuth.
1. The point above the observer that is directly opposite the nadir on the imaginary sphere against which celestial bodies appear to be projected.
2. (Figurative) The greatest height; the climax.
Uppermost point of the celestial horizon, immediately above the observer; the nadir is below, diametrically opposite. See celestial sphere.