Pertaining to the word sick
Describing something astonishing,unbelievable or suspenseful
That was so unhealthy when Brian hit that jump.
His rims are unhealthy!
Her new paint job is unhealthy!
Much like "sick" or "ill" unhealthy is the newest word used to express awe or approval of something. It can be applied to any noun but is often used in a sequence.
1. Dude that trick was unhealthy
2. Yo, this samwhich is mad ill unhealthy sick nasty