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

The densely populated island of Manhattan, with its focus on trade and commerce, was a hive of activity at the turn of the 19th century.

From The Wall Street Journal ● Sep. 13, 2026

The team compared genetic patterns associated with GLP1R activity with genes found in men who have androgenetic alopecia, the inherited form of hair loss that typically affects the top and front of the scalp.

From Science Daily ● Sep. 13, 2026

Their work has included comparing the burnt land with adjacent untouched areas, allowing researchers to measure changes in soil carbon, nutrients, microbial activity, water repellency and erosion risk.

From BBC ● Sep. 13, 2026

Raising interest rates would increase borrowing costs across the board for the US economy, acting as a brake on further investment and consumption activity.

From Barron's ● Sep. 13, 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

Mr. White, an emeritus professor of history at the University of Sydney, studied antebellum newspapers, legal documents, travelogues and paintings to glean information about black New Yorkers’ occupations, housing and leisure activities.

From The Wall Street Journal ● Sep. 13, 2026

Oram added the petition was used as "the basis of a watch list" for people carrying out "activities that were considered distasteful".

From BBC ● Sep. 11, 2026

“Thank-you notes, thank-you emails, in-person interviews … uniquely human activities are now more of a differentiator than they were before,” Link said.

From MarketWatch ● Sep. 11, 2026

Sherin argues that gathering places like coffee shops, barber shops and structured activities like job training are as critical as housing for veteran well-being.

From Los Angeles Times ● Sep. 11, 2026

Below was a drop-down box to select your zip code, followed by a checkbox list of various activities, like sports, concerts, and volunteering.

From "Sir Fig Newton and the Science of Persistence" by Sonja Thomas

Related Words

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