and no it doesn't mean cool, it means insane, when surfers say "that was a narly wave" they are saying it was insane and diffucult not that it was cool. narly is a word used to evoke an amazement that is slightly negative.
A drug addict dipshit asshole that likes to fuck over everybody and cheats on his girlfriend that he supposedly loves.
When you're in a bummy a** recording studio nodding off with thots and ignoring all your ANDROID phone calls because you're too strung out on dope to talk you're being narly and a fucking junkie.
A usually pleasant, yet versatile ajective that can be used on many different levels ranging from calm and chill, to extremely jazzed to the point of skull implosion.