1) American slang for awful 2) American slang for excellent 3) Covered with knobs or knots 4) Crooked 5) Distasteful 6) Distressing 7) Exclusively Anglo word 8) Exclusively Saxon word 9) Gnarled 10) Knobbed 11) Knotted 12) Knotty 13) Offensive 14) Sick, to surfers 15) Twisted 16) Twisted and knotty 1) Crooked 2) Gnarled 3) Knobbed 4) Too cool 
anything rough or treacherous.
Large, difficult and dangerous (usually applied to waves)
• (a.) Full of knots; knotty; twisted; crossgrained.
Gnarl'y adjective Full of knots; knotty; twisted; crossgrained. 
Gnarly is American slang for excellent.
a section of trail that’s especially rough and rugged and often steep.
Difficult conditions or terrain. See also shred the gnar.
gnarled. · distasteful; distressing; offensive; gross: a comic noted for his gnarly humor.
A word for something that is over the top extreme, radical, dangerous and/or perfect. It can be used in both positive and negative contexts. i.e that was an awesome ski run, so steep and Gnarly/his cut on his hand was really gnarly!
something particularly tough but really rather good!