An example of a zenith is the highest point in the sky.
A ten-year period in the 1980s when a career was most successful is an example of a zenith.
The zenith of her career.
Origin of zenith
- Middle English senith from Old French cenith from Medieval Latin from Arabic samt (ar-ra’s) path (over the head) from Latin sēmita path mei-1 in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition