shadowy
Definitions
Full of or characterized by shadows; dimly lit.
Indistinct, faint, or lacking clear detail.
Suspicious or of questionable character.
Examples
A shadowy figure emerged from the alleyway just as the streetlights flickered out.
The detective spent years chasing the shadowy organization responsible for the city's corruption.
She felt uneasy walking through the shadowy corridors of the old, abandoned mansion.