* Formal: The company's reliance on fax machines for communication is outmoded in today's digital age.
* Informal: That vintage dress is outmoded but still somehow chic.
* Descriptive: The museum's exhibits on ancient civilizations were outmoded and lacked engaging displays.
* Humorous: My grandpa's idea of a modern date is taking someone to a drive-in movie – talk about outmoded!
You can also use "outmoded" as a noun, though it's less common:
* The use of gas-powered cars is an outmoded practice in some parts of the world.