Definition & Meaning of "in the ascendant"in English

What is the origin of the idiom "in the ascendant" and when to use it?

The phrase "in the ascendant" is derived from the astrological term "ascendant," which refers to the sign of the zodiac that is rising on the eastern horizon at the time of a person's birth. The phrase can also be used in a more figurative sense to describe something that is growing or developing.