threaten

(verb) pose a threat to; present a danger to. Synonyms: endanger, jeopardize, jeopardise, menace, imperil, peril. Example: "The pollution is endangering the crops."

(verb) to utter intentions of injury or punishment against:"He threatened me when I tried to call the police".

(verb) to be a menacing indication of something:"The clouds threaten rain". Example: "Danger threatens."