Here are some common words you can use to describe something unfashionable:
* Out of style
* Dated
* Old-fashioned
* Unstylish
* Tacky
* Gauche
* Unfashionable
You could also use more informal words like:
* Lame
* Dorky
* Cheesy
The best word to use will depend on the context and the specific meaning you want to convey.