population

noun

pop·​u·​la·​tion ˌpä-pyə-ˈlā-shən 

1

a

: the whole number of people or inhabitants in a country or region

b

: the total of individuals occupying an area or making up a whole

c

: the total of particles at a particular energy level

—used especially of atoms in a laser

2

: the act or process of populating

3

a

: a body of persons or individuals having a quality or characteristic in common

b(1)

: the organisms inhabiting a particular locality

(2)

: a group of interbreeding organisms that represents the level of organization at which speciation begins

4

: a group of individual persons, objects, or items from which samples are taken for statistical measurement

populational

ˌpä-pyə-ˈlā-sh(ə-)nəl 

adjective

Examples of population in a Sentence

The world's population has increased greatly.

The city has experienced an increase in population.

There has been a sharp reduction in the bat population in this region.

the rural population of America

Recent Examples on the Web

However, the historic warm winter rainfall and the late-winter heatwave have caused the black fly population to explode this year. —Nicole Comstock, CBS News, 27 Mar. 2026

In Dallas-Fort Worth, there were 104,378 births and 53,559 deaths, which means 50,819 of the area’s new residents were a result of natural population change. —Eleanor Dearman, Fort Worth Star-Telegram, 26 Mar. 2026

Waxhaw’s population has doubled in size over the past decade from nearly 10,000 in 2010 to more than 20,000 in 2020. —March 26, Charlotte Observer, 26 Mar. 2026

An increase in population in Northwest Indiana could lead to an increase in federal funding for transportation projects because that funding is allocated based on a metropolitan area’s population, Vander Woude said. —Alexandra Kukulka, Chicago Tribune, 26 Mar. 2026

Word History

Etymology

borrowed from Late Latin populātiōn-, populātiō "group of people, crowd," from Latin populus people entry 1 + -ā-, stem vowel of 1st conjugation verbs + -tiōn-, -tiō, suffix of verbal action

Note: This noun appears to have been formed from a verb populāre "to people, provide with inhabitants" that is not attested before the later Middle Ages. (At the corresponding entry in the Oxford English Dictionary, third edition, a verb populāre with the sense "to increase" is cited with the date "c550 in a British source," though there is no matching record in Dictionary of Medieval Latin from British Sources.) Thesaurus Linguae Latinae has two citations for a verb populāre meaning "to show, reveal," in the Vetus Latina and Gregory of Tours, that the editor judged to be errors for prōpalāre, a derivative of classical prōpalam "in full view, openly."

First Known Use

1612, in the meaning defined at sense 1a

Phrases Containing population

• population density
• population drift
• population explosion

Rhymes for population

• abdication
• aberration
• abjuration
• abnegation
• abrogation
• acceptation
• acclamation
• acclimation
• accusation
• activation
• actuation
• acylation

Kids Definition

population

noun

pop·​u·​la·​tion ˌpäp-yə-ˈlā-shən 

1

: the whole number of people living in a country or region

2

: the act or process of populating

3

: a group of one or more species of organisms living in a particular area or habitat

Medical Definition

population

noun

pop·​u·​la·​tion ˌpäp-yə-ˈlā-shən 

1

: the whole number of people or inhabitants in a country or region

2

a

: a body of persons or individuals having a quality or characteristic in common

b(1)

: the organisms inhabiting a particular locality

(2)

: a group of interbreeding organisms that represents the level of organization at which speciation begins

3

: a group of individual persons, objects, or items from which samples are taken for statistical measurement