A riff on the archaic definition of sketch:
1. A hasty or undetailed drawing or painting often made as a preliminary study.
An outline, where not all of the elements are completely clear or known; can refer to a person, place, object or experience; frequently refers to a shady
element, something hidden and potentially dangerous; often refers to being up too long on speed and the loss of clarity that comes with sleep deprivation
Are you sure you want to give your car keys to Patrick, he seems a little sketchy.
Gurl, I was fine on day three, but day four was a little sketchy.
Angel is full-on sketchy; she would steal the teeth out of your grandmother’s mouth if she thought she wouldn’t get caught.