The phrase "keep step" can be defined as staying in alignment with someone or something else, often in a rhythmic or coordinated manner. Some synonyms for "keep step" include "maintain pace," "match stride," "follow suit," "keep time," and "adhere to rhythm." These phrases all convey a sense of staying in sync with others, whether it be in a musical context or while walking or running. Other synonyms for "keep step" may include "align," "conform," "comply," "coordinate," and "harmonize," which all speak to the idea of working together towards a common goal or following a set of guidelines.