1. a statement of an intention to inflict pain, injury, damage, or other hostile action on someone in retribution for something done or not done
2. a person or thing likely to cause damage or danger
3. the possibility of trouble, danger, or ruin

Examples

• The bully made threats against the younger students.
• She received an anonymous threat in the mail.
• Climate change poses a serious threat to coastal cities.
• The storm is a threat to outdoor activities this weekend.
• There’s always the threat of rain during the rainy season.
• The company faces the threat of bankruptcy.
• Wild animals can be a threat to hikers in the mountains.