sinister

They often have a sinister gray or red color, with warts and scales reminiscent of the toxic fungi in fairy-tale illustrations.

They were, however, assured that he lingered in the city and was sinisterly alive.

Of all these, Smith is, to the nation now, of most importance—and sinisterly so.

Karlov's agent sought his chief and found him in the cellar of the old house, sinisterly engaged.