activity

Noun

• the trait of being active; moving or acting rapidly and energetically
  • the level of activity declines with age
    

• a process existing in or produced by nature (rather than by the intent of human beings)
  • the action of natural forces
    
  • volcanic activity
    

• (chemistry) the capacity of a substance to take part in a chemical reaction
  • catalytic activity
    

• an organic process that takes place in the body
  • respiratory activity
    

• the state of being active
  • his sphere of activity
    
  • he is out of action
    

• any specific behavior
  • they avoided all recreational activity
    

Related words

• Synonyms: 
  activeness , natural process , natural action , action , bodily process , body process , bodily function
• Antonyms: 
  inactiveness , inactivity , inertia , inaction