activity

American  

[ak-tiv-i-tee] / ækˈtɪv ɪ ti /

noun

activities plural

1. the state or quality of being active.

   There was not much activity in the stock market today. He doesn't have enough physical activity in his life.

2. a specific deed, action, function, or sphere of action.

   social activities.

3. work, especially in elementary grades at school, that involves direct experience by the student rather than textbook study.

4. energetic activity; animation; liveliness.

5. a use of energy or force; an active movement or operation.

6. normal mental or bodily power, function, or process.

7. Physical Chemistry. the capacity of a substance to react, corrected for the loss of reactivity due to the interaction of its constituents.

8. Physics.

   1. the number of atoms of a radioactive substance that disintegrate per unit of time, usually expressed in curies.

   2. radioactivity.

9. an organizational unit or the function it performs.

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activity British  

/ ækˈtɪvɪtɪ /

noun

1. the state or quality of being active

2. lively action or movement

3. any specific deed, action, pursuit, etc

   recreational activities

4. the number of disintegrations of a radioactive substance in a given unit of time, usually expressed in curies or disintegrations per second

5. 1. the capacity of a substance to undergo chemical change

   2. the effective concentration of a substance in a chemical system. The absolute activity of a substance B, λ B , is defined as exp (μ B RT ) where μ B is the chemical potential

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Other Word Forms

Derived Forms

• nonactivity
  noun
• preactivity
  noun
• superactivity
  noun

Inflected Forms

Nouns

• activities
  plural

Etymology

Origin of activity

First recorded in 1520–30; from Middle French or directly from Medieval Latin āctīvitās; see active, -ity

Explanation

An activity is something you do, or just the state of doing. You might plan some indoor activities for a rainy day, or you might just rely on watching your gerbils' activity in their cage. Usually, when you use an article like an or the in front of activity, you are referring to a specific event. For example, you might search for the best activity on the cruise ship to fill your afternoon — shuffleboard, anyone? If you take the article away, and you refer to activity, you are usually referring to action. If there is too much activity on the cruise ship dance floor, you might want to avoid that zone.

Example Sentences

All this changes when both houses of Congress return after Labor Day and legislative activity ramps up.

From MarketWatch • Jul. 6, 2026

It contains the same ingredient - semaglutide - as the Wegovy weight loss injections but is still advised to be used alongside a healthy diet and increased physical activity.

From BBC • Jul. 6, 2026

New MPs must register gifts including payments in kind they received in the 12 months before election, unless they could not be "reasonably" seen as related to political activity.

From Barron's • Jul. 5, 2026

We found a consistent pattern across both parties: Members targeted by more super PAC activity were more likely to receive contributions from fellow party members and less likely to contribute to others themselves.

From Salon • Jul. 5, 2026

But their favorite activity was to stand by the windows, gaze across the city, and survey the incredible sights.

From "The Wild Robot Escapes" by Peter Brown

Related Words

• act
• endeavor
• enterprise
• job
• project
• scheme
• task
• venture
• work