adjective
sinister
SIN-ih-ster/ˈsɪnɪstər/
Suggesting evil, harm, or danger.
The host's hidden knife gives her welcoming gesture a sinister meaning.
Etymology
Latin sinister meant “left”; its deeper origin is uncertain. Through the Greek-influenced interpretation of left-side omens as unfavorable, it acquired the sense of harmful or threatening.
In context
… where sinister police billboards instruct people to snitch on those who hurt their feelings, where contentious discussions and disagreements in one’s own home can result in a knock at the door from the police …