Definify.com

Webster 1913 Edition

Adj.

Containing only an outline or rough form; being in the manner of a sketch; incomplete.

The execution is

sketchy

throughout; the head, in particular, is left in the rough.

J. S. Harford.

sketchy ‎(comparative sketchier, superlative sketchiest)

Roughly or hastily laid out; intended for later refinement.
The first draft included a sketchy design.
Resembling a comedy sketch, of sketch quality.
(slang) Of questionable or doubtful quality.
The sketchy repair job did not look like it would hold.
(slang, 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.
(slang, 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.