1. a person or thing that kills
2. something that causes death or destruction

1. extremely difficult, challenging, or exhausting
Usage: informal
2. excellent or impressive
Usage: slang

Examples

• The police are searching for the killer.
• Heart disease is a major killer in developed countries.
• That final exam was a killer.
• She wore a killer dress to the party.
• The serial killer was finally caught.
• Cancer is often called a silent killer.
• The heat wave was a killer for the elderly.
• He has a killer smile.