A comedian tells jokes for a living. If you have the ability to crack everyone up at the dinner table, your mom might say that you should be a comedian.
Comedians perform in various ways: a stand-up comedian, for example, tells jokes on a stage at a comedy club. Other comedians might perform improvisational comedy routines in a group, or be featured in a funny movie. In the 16th century, a comedian was specifically a "comic poet," while later the words comedian and actor were briefly interchangeable. It comes from the Greek komoidia, "an amusing spectacle."