|Origin:||cenith, from Arabic samt (ar-ra's) 'path (above the head)'|
zen‧ith [countable usually singular]
the most successful point in the development of something [= peak; ≠ nadir]
reach its zenith/be at its zenith
The Roman Empire reached its zenith around the year 100.
the highest point that is reached by the sun or the moon in the sky