Something that is twisted and deformed. That is extreamly out of charactor, to be extreamly non-conforming. Often used among skaters or surfers. can be good or bad
Dude bam margera is the gnarliest mother fucker alive! He is soooooo cool doing all that jackass shit! Man he has balls! He's soooooo fucking hott id tap that twice! That's why I named my dog after him dude my dog is gnarly as shit eating his own shit man that takes balls! He is wicked retarted!