Longman Dictionary of Contemporary English - threaten

~ v 1 to say that you will cause someone pain, unhappiness, or trouble if they do not do what you want  (threaten to do sth)  (Every time they quarrel, Jan threatens to leave. | threaten sb with sth)  (We were threatened with the sack if we didn't co-operate. | threaten sb)  (It's no use threatening me - I won't do it. | threaten sth)  (The unions are threatening a one-day strike. | threaten that)  (He's threatening that if he doesn't get his way, he'll resign.) 2 to be likely to harm or destroy something  (Poaching threatens the survival of the rhino.) 3 if something threatens to cause an unpleasant situation, it seems likely that it will cause it  (threaten sb/sth with)  (Large areas of the jungle are now threatened with destruction. | threaten to do sth)  (The incident threatens to ruin his chances in the election.)