"On the edge of" is a commonly used phrase to describe a situation or feeling of being close to a significant change or event. There are several synonyms for this phrase that can be used to convey a similar meaning. Some of these synonyms include "on the brink of," "at the cusp of," "nearing the precipice," "adjacent to," and "approaching the threshold." Each of these synonym phrases can be used in different contexts to describe a sense of being at a turning point or on the verge of something significant. Whether used in a personal context or to describe a larger global phenomenon, these synonyms can add depth and nuance to any writing.