Meaning "ferocious", and applicable to hot guys or people with fashion sense; people who are zesty, feisty, and assertive in life; anything that is really stylish and vogue. Also applicable to anything that is just too cool to be true; things with zing, pop, wow factor and feistiness. Antonyms: douche bag 9000, douche bag squared, lame, limp, otherwise unsatisfactory, ugly. Negative version: not ferosh.
"Henry wears a lot of Prada. That's so ferosh."
"'Members Only' jackets are not ferosh," Ben said.