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


  1. The state or quality of being active; nimbleness; agility; vigorous action or operation; energy; active force; as, an increasing variety of human activities.
    Pit row was abuzz with activity.
  2. something done as an action or a movement
    The activity for the morning was a walk to the store.
  3. something done for pleasure or entertainment, especially one involving movement or an excursion.
    Quilting can be a fun activity.
  4. Use (of internet, playstation, bank account etc.)