zenith

Definition of Zenith in English :

1. zenith

the point above the observer that is directly opposite the nadir on the imaginary sphere against which celestial bodies appear to be projected

WordNet Lexical Database for English. Princeton University. 2010.

Zenith

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

noun

1.

the point directly overhead in the sky or on the celestial sphere

n.

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.