bound·​ary | \ ˈbau̇n-d(ə-)rē How to pronounce boundary (audio) \
plural boundaries

Definition of boundary

: something that indicates or fixes a limit or extent Those two trees mark the boundary of our property. the mountain range that forms the country's northern boundary

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Other Words from boundary

boundaryless \ ˈbau̇n-​d(ə-​)rē-​ləs How to pronounce boundaryless (audio) \ adjective
boundarylessness noun

Examples of boundary in a Sentence

Those two trees mark the boundary of our property. The river forms the country's western boundary. at the boundary between fact and fiction You need to set boundaries with your children. Did he violate the boundaries of the doctor-patient relationship?
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Recent Examples on the Web

The hosts marched right back the other way on five plays, capped by a 37-yard run up the left boundary by Bob McNamara with 2:31 to go in the period. Sean Keeler, The Denver Post, "Denver Broncos home openers turn 60: Different time, same love affair," 15 Sep. 2019 The problem is enhanced in the case of rivers that flow across state boundaries. Gayathri D Naik, Quartz India, "India, leave those forests on the mountains alone, lest you want to drown," 13 Sep. 2019 Lapeze has also served on the Legislative Committee, Program Evaluation Committee and Student Attendance Area Committee, which determines boundaries. Chris Shelton, Houston Chronicle, "Familiar face returns after Cunningham resigns from Humble ISD school board," 12 Sep. 2019 The theater group collaborates with a diverse community of Chicagoans to create original theatrical experiences that push artistic boundaries and explore critical social issues. Darcel Rockett,, "Night Out in the Parks kicks off this week with Collaboraction’s collection of 21 premiere works of theater, dance, music in ‘Peacebook’," 12 Sep. 2019 To almost everyone, their prim boundary-drawing seemed unnatural and incorrect in a context defined by its spontaneity, emotionality, and complicated relationship with taboo. Wired, "Concerning Consent, Chappelle, and Canceling Cancel Culture," 8 Sep. 2019 Fire growth causes road closures Due to the fire, Table Mesa Road was closed from the Tonto National Forest boundary on the west to a junction with Forest Road 24 (Seven Springs), according to officials. Chelsea Curtis, azcentral, "3 lightning-caused fires see growth overnight in Tonto National Forest," 7 Sep. 2019 And that success has allowed him to test different boundaries off the field. Albert Breer,, "Just How Far Can Antonio Brown Push His Limits? Very Far, Apparently," 6 Sep. 2019 Walls can be thin, and balconies are effectively shared space, but not every cruiser recognizes those boundaries. Mark Ellwood, Condé Nast Traveler, "Cruise Ship Etiquette Tips: A Primer For Before You Sail," 4 Sep. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'boundary.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of boundary

1598, in the meaning defined above

History and Etymology for boundary

bound entry 6 + -ary entry 1

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Statistics for boundary

Last Updated

19 Sep 2019

Look-up Popularity

Time Traveler for boundary

The first known use of boundary was in 1598

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More Definitions for boundary



English Language Learners Definition of boundary

: something (such as a river, a fence, or an imaginary line) that shows where an area ends and another area begins
: a point or limit that indicates where two things become different
: unofficial rules about what should not be done : limits that define acceptable behavior


bound·​ary | \ ˈbau̇n-də-rē How to pronounce boundary (audio) , ˈbau̇n-drē\
plural boundaries

Kids Definition of boundary

: something that points out or shows a limit or end : a dividing line


plural boundaries

Legal Definition of boundary

: a theoretical line that marks the limit of an area of land

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More from Merriam-Webster on boundary

Rhyming Dictionary: Words that rhyme with boundary

Thesaurus: All synonyms and antonyms for boundary

Spanish Central: Translation of boundary

Nglish: Translation of boundary for Spanish Speakers

Britannica English: Translation of boundary for Arabic Speakers

Comments on boundary

What made you want to look up boundary? Please tell us where you read or heard it (including the quote, if possible).


miscellaneous remnants or debris

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