1.
The ~ of something such as someone’s career or the history of an organization is its worst time. (LITERARY)
1945 to 1946 was the ~ of Truman’s presidency.
? zenith
N-SING: usu with poss
2.
In astronomy, the ~ is the point at which the sun or moon is directly below you, on the other side of the earth. Compare zenith . (TECHNICAL)
N-SING: the N