The opposite of nadir, it's from the Arabic for "road above"
1350-1400; Middle English cenith < Medieval Latin < Old 
Spanish ... (compare Arabic samt ar-rs road above (over) one's head, the 
opposite of nadir) ... As summer reaches its zenith, these landscapes provide a 
welcome... [DOC] [TLE] Nadir - definition of nadir by The Free Dictionary [PAR] zenith, nadir - Zenith derived from Arabic samt ar-ras, "the way or road above 
one's head"; zenith ... zenith - the point above the observer that is directly 
opposite the nadir on the imaginary sphere against ... Want to thank TFD for its 
existence?