1. The point on the celestial sphere that is directly above the observer.
2. The upper region of the sky.
3. The highest point above the observer's horizon attained by a celestial body.
4. The point of culmination; the peak: the zenith of her career. See Synonyms at summit.
[Middle English senith, from Old French cenith, from Medieval Latin, from Arabic samt (ar-ra's), path (over the head), from Latin sēmita, path; see mei-1 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.