Passe (adjective)

1. No longer fashionable, out of date, outdated or old-fashioned.
2. Outmoded or no longer acceptable or current.
3. No longer relevant or important.

Origin:

From french passé, meaning past or gone by.

Examples:

1. Her fashion sense is so passe, she needs a complete wardrobe makeover.
2. The use of flip phones is passe, most people have smartphones now.
3. His ideas about gender roles are passe and don't reflect modern thinking.