There are a number of great synonyms for the phrase "in ascendency." Some of the best of these include "on the rise," "gaining ground," "making progress," "ascending," "on the upswing," and "moving forward." Each of these phrases conveys the sense that something is growing and becoming more powerful or prominent, whether that's a person, an idea, a movement, or something else entirely. No matter which phrase you use, however, the key is to capture that sense of momentum, progress, and upward mobility that characterizes anything that is "in ascendency." Whether you're writing about business, politics, or personal development, this phrase is an important one to know and use.