The phrase “a must watch” refers to something—typically a movie, TV show, or documentary—that is highly recommended and considered essential viewing. It suggests that the content is so engaging, informative, or entertaining that missing it would be a significant loss. People often use this expression to indicate that they believe others should prioritize watching it based on its quality, impact, or cultural relevance. Essentially, if something is labeled as a “must watch,” it signifies that it has garnered enough acclaim or interest to warrant attention from viewers.