activity

[ak-tiv-i-tee]

SEE MORE SYNONYMS FOR activity ON THESAURUS.COM

noun, plural ac·tiv·i·ties.

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.

a specific deed, action, function, or sphere of action: social activities.

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

energetic activity; animation; liveliness.

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

normal mental or bodily power, function, or process.

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

Physics.

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

an organizational unit or the function it performs.

Origin of activity

1520–30; (< Middle French) < Medieval Latin āctīvitās. See active, -ity

Related formsnon·ac·tiv·i·ty, noun, plural non·ac·tiv·i·ties.pre·ac·tiv·i·ty, noun, plural pre·ac·tiv·i·ties.su·per·ac·tiv·i·ty, noun, plural su·per·ac·tiv·i·ties.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for activity

action, life, enterprise, exercise, movement, task, work, project, job, venture, act, endeavor, scheme, exertion, motion, labor, liveliness, animation, bustle, hustle

Examples from the Web for activity

Contemporary Examples of activity

For me, I just like the activity, and the activity just happens to make money.
The Gospel According to Nick Denton—What Next For The Gawker Founder?
Lloyd Grove
December 14, 2014
Power generation and production is not the sort of activity one usually associates with skiing.
Solar Powered Ski Lift
The Daily Beast
November 24, 2014
If a person looks like they are alive, but their brain shows no signs of activity, is this person dead or alive?
What It’s Like to Wake Up Dead
Dr. Anand Veeravagu, MD, Tej Azad
November 21, 2014
It is also overwhelmingly pro-regime, and since the start of Syrian unrest the region has become a hotbed of pro-Assad activity.
Welcome to Assadville, USA
Christopher Moraff
November 11, 2014
The play of Sunday, the play of being angels in the choir, is not just a peripheral secondary marginal realm of activity.
Joseph Campbell on the Roots of Halloween
Joseph Campbell
October 31, 2014

Historical Examples of activity

Early were hammers ringing on anvils in the Dragon Court, and all was activity.
The Armourer's Prentices
Charlotte M. Yonge
Its attributes of youth are the activity and eager life with which it is redundant.
Sketches from Memory
Nathaniel Hawthorne
The vigilance and activity of Nicias never relaxed for a moment.
Stories from Thucydides
H. L. Havell
His energy and activity throughout the march is described as intense.
Camps, Quarters and Casual Places
Archibald Forbes
Though wounded, they had retained their strength and activity in battle.
Beowulf
Unknown

British Dictionary definitions for activity

activity

noun plural -ties

the state or quality of being active

lively action or movement

any specific deed, action, pursuit, etcrecreational activities

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

the capacity of a substance to undergo chemical change
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

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for activity

c.1400, "active or secular life," from Old French activité, from Medieval Latin activitatem (nominative activitas), a word in Scholastic philosophy, from Latin activus (see active). Meaning "state of being active, briskness, liveliness" recorded from 1520s; that of "capacity for acting on matter" is from 1540s.

activity in Medicine

activity

[ăk-tĭv′ĭ-tē]

n.

A physiological process.

The presence of neurogenic electrical energy in electroencephalography.

An ideal concentration for which the law of mass action will apply perfectly.

The intensity of a radioactive source.

The ability to take part in a chemical reaction.