"Widely known" refers to something that is familiar to a large number of people. There are numerous other ways to express the same idea, depending on the context. Some alternatives include "popular," "famous," "renowned," "well-known," "notorious," "recognized," "celebrated," "established" and "publicized." These synonyms can be used interchangeably when describing someone who has gained widespread recognition, such as a celebrity or public figure, or when referring to a commonly known fact or piece of information. The choice of word will depend on the tone of the sentence and the writer's intent.