The phrase "the upper hand" means to have control or dominance over a situation or person. There are several synonyms to describe this feeling of power, including "advantage," "dominance," "superiority," "supremacy," "ascendancy," and "influence." These terms refer to the ability to direct or influence events and outcomes in one's favor. Other synonyms include "preeminence," "command," "authority," "sovereignty," and "dominion," which evoke a sense of leadership or rulership. Essentially, any word that suggests having the upper hand implies a sense of control and power over others, whether through strategic planning or sheer force of will.