What is the antonym of "zenith"?

The antonym of "zenith" is "nadir." The term "zenith" refers to the highest point or peak, often used in various contexts such as astronomy or figuratively to indicate the pinnacle of success or achievement. In contrast, "nadir" signifies the lowest point, representing the opposite end of the spectrum.

In many ways, these two terms can be viewed as opposites: one describing the apex and the other indicating the abyss. Understanding this relationship between the two words highlights their positions on a conceptual scale, where one represents ascension and the other, descent. This clarity in meaning creates a stark contrast, making "nadir" the correct antonym for "zenith."

The other options listed do not serve as true antonyms. Terms like "climax," "acme," and "summit" all denote high points or peak experiences and, therefore, do not reflect the opposite meaning of "zenith."