define

verb

de·​fine di-ˈfīn 

defined; defining

transitive verb

1

a

: to determine or identify the essential qualities or meaning of

whatever defines us as human

b

: to discover and set forth the meaning of (something, such as a word)

how the dictionary defines "grotesque"

c

computing : to create with established rules or parameters

define a window

define a procedure

2

a

: to fix or mark the limits of : demarcate

rigidly defined property lines

b

: to make distinct, clear, or detailed especially in outline

the issues aren't too well defined

eyes defined by mascara

3

: characterize, distinguish

you define yourself by the choices you make

—Denison Univ. Bull.

the moment that defined the campaign

intransitive verb

: to make a definition (see definition sense 1a)

definement

di-ˈfīn-mənt 

noun

definer

di-ˈfī-nər 

noun

Synonyms

• delineate
• outline
• silhouette
• sketch
• trace

Examples of define in a Sentence

a term that is difficult to define

The government study seeks to define urban poverty.

Her book aims to define acceptable social behavior.

She believes that success should be defined in terms of health and happiness.

That fence defines the far edge of the property.

Recent Examples on the Web

Sadly, today’s political revolt is divorced from the cultural and artistic values that define and empower humanity. —Natasha Gural, Forbes.com, 8 May 2025

The series explores how Bao personifies the idealism and adventurism that defined the city in the 1990s. —Andreas Wiseman, Deadline, 8 May 2025

Before the pandemic, before widespread calls for racial justice, the show captures the quiet anxieties that defined so many Black households. —Okla Jones, Essence, 8 May 2025

The pattern that defined this period—an uptick in spying during war, and then its ebbing in peacetime—poses a problem for Rogg and Lowenthal, whose accounts of the years between the Revolution and World War II are overstuffed with desultory detail. —James Santel, The Atlantic, 8 May 2025

Word History

Etymology

Middle English diffinen, defynen, borrowed from Anglo-French definer, diffiner, borrowed (with conjugation change) from Medieval Latin dēfīnīre, diffīnīre (dif- by association with dif-, assimilated form of dis- dis-), going back to Latin dēfīnīre "to mark the limits of, determine, give an exact description of," from dē- de- + fīnīre "to mark out the boundaries of, limit" — more at finish entry 1

First Known Use

14th century, in the meaning defined at transitive sense 1a

Phrases Containing define

• broadly/loosely define
• narrowly define
• pre-define

Rhymes for define

• affine
• airline
• align
• aline
• assign
• baseline
• beamline
• benign
• bloodline
• bovine
• byline
• canine

Kids Definition

define

verb

de·​fine di-ˈfīn 

defined; defining

1

a

: to determine the essential qualities of

define the idea of loyalty

define a circle

b

: to set forth the meaning of

define a word

c

: to specify (as a programming task) for a computer to use

define a procedure

2

a

: to fix or mark the limits of

the boundary was clearly defined

b

: to make distinct, clear, or detailed especially in outline

the tree was well defined against the sky

your argument is not well defined

definable

-ˈfī-nə-bəl

adjective

definer noun

Etymology

Middle English definen "to define, mark the limits of," Latin definire (same meaning), from Latin de- "from, away" and finire "to limit," from finis "end, limit" — related to final, finish, infinity