Definition

Questionable, suspicious, or unreliable; not quite trustworthy or potentially risky. Can describe people, situations, plans, or information that seem shady or incomplete.

Example Usage

That deal sounds sketchy to me—I'd rather not get involved.

Origin

From the adjective 'sketch,' meaning rough or incomplete (as in a sketch drawing), extended to mean morally or logically incomplete, hence suspicious.

Fun Fact

The term gained wider popularity in the 1980s-90s among skateboard and surf cultures in California before going mainstream.

Source: Definition backfill (hailey)