Roughly or hastily laid out; intended for later refinement.
The first draft included a sketchy design.
Resembling a comedy sketch, of sketch quality.
Of questionable or doubtful quality.
The sketchy repair job did not look like it would hold.
(of a person) Suspected of taking part in illicit or dishonorable dealings.
Because he is so sketchy, I always think that he is up to something.
(of a person) Disturbing or unnerving, often in such a way that others may suspect them of intending physical or sexual harm or harassment.
Jack is so sketchy. I think he's stalking me.