activity

any specific activity

• “they avoided all recreational activity”

the state of being active

• “his sphere of activity”
• “he is out of action”

an organic process that takes place in the body

• “respiratory activity”

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

• “catalytic activity”

a process existing in or produced by nature (rather than by the intent of human beings)

• “the action of natural forces”
• “volcanic activity”

the trait of being active; moving or acting rapidly and energetically

• “the level of activity declines with age”