1: amazingly deep fresh powder snow
2: an insanely awesome line down a step mountain face.
3: A big ballsy jump off a cliff or in a terrain park
4: Anything that is 'off the hook' epic and worthy of such status
An portmanteau of the the popular adjective "sick", a word extensively used in the snow sports community and "tarded" from retarded. Something so good it profoundly affects you .
...yeah, that was sicktarded!
Did you get out in Hakuba after the epic dump?
....yeah sure did, it was nipple deep and sicktarded, pure sicktarded.