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

• trace
• outline
• delineate

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

The fallout from all this has defined an especially dramatic week in Spanish football. —Dermot Corrigan, New York Times, 25 Oct. 2025

Records, milestones and multiple Pro Bowl have defined both players’ careers. —Blair Kerkhoff, Kansas City Star, 24 Oct. 2025

Jazz In recent years, the pianist Vijay Iyer and the drummer Tyshawn Sorey, defining composers and leaders of contemporary jazz, have become one of its most formidable pairings. —Hilton Als, New Yorker, 24 Oct. 2025

That balance between art and audience, Cienfuegos argues, defines what Seminci stands for. —Emiliano De Pablos, Variety, 24 Oct. 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