activity activity /ækˈtɪvəti/

noun

1. () Any specific behavior  ( activity )
   any specific behavior
    They avoided all recreational activity
   they avoided all recreational activity
   
   
2. () The state of being active  ( activeness , action , activity )
   the state of being active
    His sphere of activity
   his sphere of activity
    He is out of action
   he is out of action
   
3. () An organic process that takes place in the body  ( bodily process , body process , bodily function , activity )
   an organic process that takes place in the body
    Respiratory activity
   respiratory activity
   
4. The trait of being active; moving or acting rapidly and energetically  ( activeness , activity )
   the trait of being active; moving or acting rapidly and energetically
    The level of activity declines with age
   the level of activity declines with age
   
5. A process existing in or produced by nature (rather than by the intent of human beings)  ( activity , natural action , natural process , action )
   a process existing in or produced by nature (rather than by the intent of human beings)
    The action of natural forces
   the action of natural forces
    Volcanic activity
   volcanic activity
   
6. (chemistry) the capacity of a substance to take part in a chemical reaction  ( activity )
   (chemistry) the capacity of a substance to take part in a chemical reaction
    Catalytic activity
   catalytic activity