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

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Etymology

Origin of activity

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

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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

See Examples For:

activity activities

Rather than killing soldiers and destroying property, AI could increasingly influence an adversary’s capacity and willingness to continue fighting by disrupting economic activity, military production, logistics, communications and financial systems.

From The Wall Street Journal ● Oct. 28, 2026

Cardiolipin helps maintain the membrane's distinctive folded architecture, which is essential for proper mitochondrial activity.

From Science Daily ● Oct. 28, 2026

Officers say they are also aware of images circulating online, suggesting "planned protest activity" will take place in Glasgow the same night.

From BBC ● Oct. 28, 2026

Surfing, with 81, is by far the No. 1 activity associated with incidents involving sharks.

From Los Angeles Times ● Oct. 28, 2026

We were woken hours later by the noise of it docking, and the buzz of activity that followed.

From "Flying Through Water" by Mamle Wolo

Ants depend heavily on chemical cues to find their way through the environment, identify members of their own colonies, and coordinate activities with other ants.

From Science Daily ● Oct. 28, 2026

Previously better known as an aircraft engine manufacturer, the pivot follows its 2025 acquisition of the flight controls and actuation activities of US-based Collins Aerospace for $1.8 billion.

From Barron's ● Oct. 28, 2026

With the overwhelming amount of travel accounts on TikTok, Instagram and blogs, how do I identify activities and recommendations within my price range?

From MarketWatch ● Oct. 28, 2026

Since then, she had focused on exercising through activities such as gym workouts and running, as well as going to therapy to improve her wellbeing, she added.

From BBC ● Oct. 26, 2026

Valerie Blakeman, the wife of Dad’s previous boss, and the volunteer and activities coordinator here.

From "Red Flags and Butterflies" by Sheryl Azzam

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Related Words

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

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