Definition

Morally questionable, dishonest, or suspicious; involving deception or illicit activity. Also used to describe someone untrustworthy or behavior that seems underhanded.

Example Usage

He's been doing some shady business deals that nobody wants to talk about.

Origin

From the literal meaning of 'shade' (darkness or shadow), metaphorically extended to mean 'obscured' or 'hidden,' implying something not in the light.

Fun Fact

The term has been in use since at least the 1920s, though it gained renewed popularity in hip-hop and African American Vernacular English.

Source: Definition backfill (hailey)