Outmoded is an adjective that is often used to describe something that is no longer fashionable, modern, or relevant. There are many synonyms that can be used to describe something that is outmoded, including outdated, antiquated, old-fashioned, obsolete, archaic, passe, unfashionable, behind the times, and retrograde. These words all convey a sense that something is no longer in use or has fallen out of favor, and can be used to describe a wide range of things from fashion trends to technology. When looking for a synonym for outmoded, it is important to consider the context in which the word is being used, as some words may be more appropriate than others depending on the situation.