The English language is rich in synonyms for the phrase "impress greatly." Some of these include astound, amaze, awe, bewitch, captivate, dazzle, enchant, fortify, galvanize, hypnotize, inspire, mesmerize, overwhelm, stun, and sway. Each of these terms carries its own nuances and connotations, allowing a writer or speaker to convey a specific meaning and effect. For example, "astound" is often used to describe a sudden and unexpected overwhelming feeling, while "dazzle" is more commonly used to describe a momentary and visually striking experience. Whatever the occasion, there is sure to be a perfect synonym for "impress greatly" to capture the spirit of the moment.