zenith

American  

[zee-nith, zen-ith] / ˈzi nɪθ, ˈzɛn ɪθ /

noun

1. the point on the celestial sphere vertically above a given position or observer.

   Antonyms:

   nadir

2. a highest point or state; culmination.

   Synonyms:

   summit, apex

   Antonyms:

   nadir

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zenith British  

/ ˈziːnɪθ, ˈzɛnɪθ /

noun

1. astronomy the point on the celestial sphere vertically above an observer

2. the highest point; peak; acme

   the zenith of someone's achievements

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zenith Scientific  

/ zē′nĭth /

1. The point on the celestial sphere that is directly above the observer (90 degrees above the celestial horizon).

2. Compare nadir

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Other Word Forms

• zenithal adjective

Etymology

Origin of zenith

1350–1400; Middle English cenith < Medieval Latin < Old Spanish zenit, scribal error for zemt < Arabic samt road, incorrectly read as senit by medieval scribes (compare Arabic samt ar-rās road above (over) one's head, the opposite of nadir )

Explanation

Zenith means the high point — it comes from astronomy, where it describes the highest point in an arc traveled by a star or a planet or another celestial body. The sun reaches its zenith when it is as high in the sky as it is going to go on that day. Zenith — and its opposite, nadir — have been appropriated by non-astronomers and are used to describe high and low points in non-astronomical contexts. For example, you can say that the high school quarterback hit his zenith in high school, and it was all downhill from there. Do yourself a favor and try to delay your zenith so you'll have something to look forward to in your future!

Example Sentences

It did so for the same reason Britain championed free trade when it was at its zenith of industrial power in the 19th century: It knew it was going to win.

From Barron's • Mar. 20, 2026

That reputation had reached its zenith by late 2024, when the firm was drawing takeover interest.

From The Wall Street Journal • Feb. 11, 2026

Standing on a stage and clutching a Grammy as the world watches on is, arguably, the zenith of stardom.

From BBC • Feb. 3, 2026

When Congress and the president act in concert, the president’s power is at its zenith.

From Slate • Sep. 1, 2025

It reached what they were certain must be the zenith of its curve, and then, defying all reason, it continued to rise into the air.

From "Stardust" by Neil Gaiman