activity

[ak-tiv-i-tee]

noun

plural

activities 

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.

activity

/ 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

Other Word Forms

• nonactivity noun
• preactivity noun
• superactivity noun

Word History and Origins

Origin of activity¹

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

Example Sentences

Are we to believe that this type of activity does not occur in other sports as well as other levels of sports?

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These neural circuits track critical processes including circulation, digestion, and immune activity.

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This slow breakup helps explain puzzling features from Earth's past, such as abandoned fragments of old tectonic plates and bursts of volcanic activity in unexpected places.

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Homework needs to be meaningful, given that it can increase student stress and can get in the way of positive interactions with family members and peers, valuable extracurricular activities and even sleep, experts said.

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Drugs that fine-tune C/EBPα activity, for example, could help AT2 cells rebuild lung tissue more effectively or reduce scarring in conditions like pulmonary fibrosis.

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Related Words

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