An adjective used to describe someone or something that exhibits strong characteristics of being alternative or pertaining to alternative subculture.
I'm surprised Merriweather Post Pavilion cracked the Top 20 in the Billboard 200; Animal Collective
is Uber Alt.
Five years ago he was listening to Maroon 5, now he's going to Mastodon
concerts and dating an Uber Alt chick that has more tattoos and piercings than him.