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

See Examples For:

activity activities

However, doing higher levels of activity after losing weight was strongly linked to maintaining the weight loss.

From Science Daily ● Aug. 22, 2026

"As such, I respectfully ask you in the name of football to reconsider your attendance as it will unfortunately undermine the technical nature of this important youth development activity."

From BBC ● Aug. 22, 2026

Carney has also tried to jumpstart domestic economic activity through his Major Projects Office, set up to reduce bureaucratic delays and grant quicker approval for select large-scale infrastructure initiatives.

From Barron's ● Aug. 22, 2026

Artificial intelligence was then used to analyze patterns of brain activity across people of different ages.

From Science Daily ● Aug. 22, 2026

For a moment I just stood there, taking it all in: the flashes of color, the blur of activity.

From "The Red Car to Hollywood" by Jennie Liu

Fall activities are just around the corner, so Jason Gay is celebrating the youth sports parents—those who don’t resort to screaming at teen refs or fistfighting in the parking lot.

From The Wall Street Journal ● Aug. 22, 2026

Australian police charged a man with foreign interference on Friday for allegedly seeking to pass intelligence about Ukrainian military activities to Russia.

From Barron's ● Aug. 21, 2026

The Alpine Graubünden region, also known as Grisons, is a popular holiday destination for both winter sports and summer nature activities in eastern Switzerland.

From BBC ● Aug. 21, 2026

Ranch activities include hurtling through agility courses, swimming beneath a massive artificial waterfall and roaming sprawling fantasy playgrounds built expressly for their entertainment.

From Los Angeles Times ● Aug. 21, 2026

These songs are part of a potentially rich musical experience for the child—exposing them to material with inherent sociocultural meaning that can contribute to excellent lessons and, most importantly, enhance integration activities.

From "Music and the Child" by Natalie Sarrazin

Related Words

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