activity
UK: ækˈtɪvəti | US: ækˈtɪvəti
n. 1. The state or quality of being active; movement or action.
n. 2. A specific action or task, often organized or purposeful.
n. 3. (Chemistry) The effective concentration of a substance in a system.
The word "activity" originates from the Latin activitas, derived from actus (past participle of agere, meaning "to do" or "to drive"). The root act preserves the core idea of action, while the suffix -ivity (via Old French -ivité) transforms it into a noun describing the state or capacity of acting. This logical progression—from verb to noun—reflects how Latin roots were adapted into English to abstractly conceptualize dynamic states.
Regular physical activity improves overall health.
The volcano showed signs of increased seismic activity.
She organized a team-building activity for the employees.
The enzyme's activity was measured in the lab.
His mental activity was evident in his rapid problem-solving.