1. made active or operational; turned on or put into action
2. treated or processed to increase effectiveness or reactivity
Usage: chemistry; technical

Examples

• The security system was activated when we left the house.
• She activated her credit card by calling the bank.
• The emergency beacon activated automatically after the crash.
• Activated charcoal is used in water filters.
• The software license needs to be activated online.
• His account was activated within 24 hours.
• The alarm was activated by motion in the hallway.