The combination of the words "Nasty" and "Sketchy". Also can be shortened to just "Netch". This word that can be used to describe any person, place or thing. Especially used when describing a person who is dirty, suspicious or questionable in character or appearance.
Ewww...That dude is totally netchy!
That toilet is netch!!!!!
Eating Taco Bell while sober is definatley Netch!