activity

noun

ac·​tiv·​i·​ty ak-ˈti-və-tē 

plural activities

1

: the quality or state of being active : behavior or actions of a particular kind

physical activity

criminal activity

economic activity

2

: vigorous or energetic action : liveliness

a scene of excitement and activity

3

: natural or normal function: such as

a

: a process (such as digestion) that an organism carries on or participates in by virtue of being alive

b

: a similar process actually or potentially involving mental function

specifically : an educational procedure designed to stimulate learning by firsthand experience

4

: an active force

5

a

: a pursuit in which a person is active

business activities

social activities

b

: a form of organized, supervised, often extracurricular recreation

The camp offers hiking, swimming, and other activities.

6

: an organizational unit for performing a specific function

also : its function or duties

the restaurant inspection activity of the health department

Synonyms of activity

• exertion
• conditioning
• exercise

Examples of activity in a Sentence

The holidays always set off a lot of activity in our home.

the sexual activity of married couples

The police are now monitoring criminal activity in the area.

She gets at least 30 minutes of physical activity every day.

The instruments are used to detect volcanic activity on the island.

We planned an activity for the children.

Recent Examples on the Web

The Russian general was one of several GRU officials sanctioned by the United States in 2016 for wide-ranging malicious cyber activity directed at undermining US democratic processes. —Anna Chernova, CNN Money, 6 Feb. 2026

The team recorded the neuron’s electrical activity to test whether the process could produce distinguishable signals. —Matthew S Williams, Interesting Engineering, 5 Feb. 2026

Miller similarly fits the age profile at 22 and balances out the composition of the roster, which skewed heavily toward guards in the flurry of trade activity this week. —Julia Poe, Chicago Tribune, 5 Feb. 2026

Before Moscow suspended New START in 2023, both parties carried out 328 on-site inspections and exchanged more than 25,000 notifications about each other’s activities, according to the State Department. —Yuliya Talmazan, NBC news, 5 Feb. 2026

Word History

Etymology

Middle English actyvete "active life," borrowed from Middle French & Medieval Latin; Middle French activité "power of acting, exercise of this power," borrowed from Medieval Latin āctīvitāt-, āctīvitās (Late Latin, "active form of a verb"), from Latin āctīvus active entry 1 + -itāt-, -itās -ity

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing activity

• bitten by the (activity) bug
• co-activity
• optical activity
• self-activity

Rhymes for activity

• acclivity
• captivity
• declivity
• festivity
• nativity
• passivity
• proclivity
• absorptivity
• affectivity
• collectivity
• conductivity
• connectivity

Kids Definition

activity

noun

ac·​tiv·​i·​ty ak-ˈtiv-ət-ē 

plural activities

1

: the quality or state of being active

2

: forceful or energetic action

3

: a natural, normal, or assigned function: as

a

: a process that an organism carries on or participates in by virtue of being alive

b

: a similar process that involves or is capable of involving mental function

4

: an educational exercise designed to teach by firsthand experience

5

: an active force

solar activity

6

a

: something done especially for relaxation or fun

b

: a form of organized recreation

Medical Definition

activity

noun

ac·​tiv·​i·​ty ak-ˈtiv-ət-ē 

plural activities

1

: natural or normal function: as

a

: a process (as digestion) that an organism carries on or participates in by virtue of being alive

b

: a similar process actually or potentially involving mental function

specifically : an educational procedure designed to stimulate learning by firsthand experience

2

: the characteristic of acting chemically or of promoting a chemical reaction

the activity of a catalyst