to say you will hurt, punish, or cause trouble for someone if they do not do what you want
The bully threatened Sam with a punch unless he handed over his lunch money.
During the meeting, the angry customer threatened to sue the company if they didn't issue a refund.
to seem likely to cause harm or danger in the future
Dark clouds threatened rain, so we packed up the picnic early.
Rising sea levels threaten many coastal towns around the world.
