shady

"her shady past intrigued him"; "a shady part of town";

"there was something fishy about the accident"; "up to some funny business"; "some definitely queer goings-on"; "a shady deal"; "her motives were suspect"; "suspicious behavior";

"He established a dummy company through which he laundered vast sums of cash from shady middlemen and arms dealers";

"the shady side of the street"; "the surface of the pond is dark and shadowed"; "we sat on rocks in a shadowy cove"; "cool umbrageous woodlands";