• Action (philosophy), in general

• the Aristotelian concept of energeia, Latinized as actus

• physical activity

• mental activity

• Activity (chemistry)

• Activity (UML)

• Activity, an alternative name for the game charades

• Activity, a task.

• Activity, the ability of a piece to influence the game in chess

• Activity, the rate of a catalytic reaction, such as enzyme activity, in physical chemistry and enzymology

• activity (chemistry), the effective concentration of a solute for the purposes of mass action

• activity (project management)

• activity (radioactivity), the number of radioactive decays per second

• activity (software engineering)

• activity (soil mechanics)

• activity diagram, a diagram representing activities in UML

• Activity, a board game by Piatnik & Söhne

• HMS Activity (D94), an aircraft carrier of the Royal Navy

• in military parlance, a military agency or unit (e.g. Intelligence Support Activity)

See also

• Energy (disambiguation)