There are many synonyms for the phrase "stop running" which can be used in various situations, such as halting a person or object in motion or ending a particular activity. Some possible alternatives include "cease running," "halt," "stand still," "come to a stop," "pause," "dismount," "discontinue," "terminate," "abandon," "quit," "end," "finish," "wrap up," "put a halt to," "bring to a halt," and "call off." These synonyms convey similar meanings and can be used interchangeably depending on the intended context and level of formality. By using these synonyms, writers and speakers can avoid repetition and add variety to their language.