Byword

noun

1. A proverb or proverbial expression, common saying; a frequently used word or phrase.
2. A characteristic word or expression; a word or phrase associated with a person or group.
3. Someone or something that stands as an example (i.e. metonymically) for something else, by having some of that something's characteristic traits.
4. An object of notoriety or contempt, scorn or derision.
5. A nickname or epithet.