1. (

• endanger ,
• jeopardize ,
• jeopardise ,
• menace ,
• threaten ,
• imperil ,
• peril

) pose a threat to; present a danger to; "The pollution is endangering the crops" ;

2. (

• menace

) express a threat either by an utterance or a gesture; "he menaced the bank manager with a stick" ;

3. (

• menace

) act in a threatening manner; "A menacing person" ;

1. (

• baleful ,
• forbidding ,
• menacing ,
• minacious ,
• minatory ,
• ominous ,
• sinister ,
• threatening

) threatening or foreshadowing evil or tragic developments; "a baleful look"; "forbidding thunderclouds"; "his tone became menacing"; "ominous rumblings of discontent"; "sinister storm clouds"; "a sinister smile"; "his threatening behavior"; "ugly black clouds"; "the situation became ugly" ;