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1. Causing motion, action or change
   "The aeroplane has self-activating flaps on the wings";
   - actuating

1. The activity of causing to have energy and be active
   - energizing, activation, energising [Brit]

1. Put in motion, initiate (a device, reaction, circuit, etc)
   "activate the circuits";
   - actuate, trigger, set off, spark off, spark, trigger off, touch off
    
2. Make active or more active
   "activate an old file"
    
3. Make more adsorptive
   "activate a metal"
    
4. Aerate (sewage) so as to favour the growth of organisms that decompose organic matter
   - aerate
    
5. Make (substances) radioactive

See also: causative

Type of: activity, alter, change, initiate, modify, pioneer

Antonym: inactivate

Encyclopedia: Activate