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

With the assistance of more than 400 philanthropic leaders and influential leaders, Power Lunch has raised over $33 million to date to provide nourishing meals to New York City’s aging population. —Fairchild Studio, Footwear News, 11 Nov. 2025

So many, in fact, that Miami’s population of millionaires nearly doubled in the decade to 2024. —Max Klaver, Miami Herald, 11 Nov. 2025

Unless Arizona’s farmers and tribes can strike deals to bail out the state’s growing cities, the largest population centers could start to face water restrictions on the Colorado River. —Austin Corona, AZCentral.com, 11 Nov. 2025

According to the National Institute for Occupational Safety and Health, firefighters have a 9% higher risk of being diagnosed with cancer and a 14% higher risk of dying from cancer than the general population. —Laura Schulte, jsonline.com, 11 Nov. 2025

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