activity

An organic process that takes place in the body.

“respiratory activity”

The state of being active.

“his sphere of activity”

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).

“volcanic activity”

Any specific behavior.

“they avoided all recreational activity”

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

“catalytic activity”