1. a person who is actively opposed or hostile to someone or something
2. a hostile nation or its armed forces or citizens, especially in time of war
Usage: military
3. something that harms or weakens something else

Examples

• He made many enemies during his rise to power.
• The two countries have been enemies for decades.
• Enemy forces attacked at dawn.
• She considered him her worst enemy after the betrayal.
• Procrastination is the enemy of success.
• The soldiers were captured by enemy troops.
• Time is often the enemy of perfection.