"Caught on" is a phrasal verb that expresses the idea of something becoming popular or trendy. There are various synonyms for "caught on" that can be used to convey the same meaning. For instance, the phrase "gone viral" refers to something that has rapidly gained widespread attention or popularity on social media. Similarly, the words "trending" or "buzzing" imply that something is currently popular. The phrase "become a sensation" can also be used to convey the same idea. Furthermore, the term "caught the public's eye" implies that something has captured people's attention and become well-known in a relatively short duration. By using these synonyms, one can easily convey the notion of something becoming a trend or a fad.