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

Other Words from boundary

boundaryless \ ˈbau̇n-​d(ə-​)rē-​ləs How to pronounce boundary (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 Both maps stop their southernmost district at the southern boundary of the Municipality. James Brooks, Anchorage Daily News, 10 Sep. 2021 Mohajir, who is behind the boundary-bending South Asian street food spot Wazwan, is preparing to reveal its fine dining neighbor, Aman, this week. Alyson Sheppard, Robb Report, 5 Nov. 2021 The distillery has long taken pride in the creativity of its whisky makers, with a stream of boundary-pushing blends coming from its famously tall—the tallest in Scotland—copper stills mimicking the necks of giraffes. Lauren Jade Hill, Forbes, 26 Oct. 2021 The data gathered from Soars experiments about the boundary between air and water can then be used to improve coarser global climate models by plugging this new fine-scale data into them. Matt Simon, Wired, 26 Oct. 2021 In a pandemic, when the stakes are highest, the somewhat porous boundary between these publication worlds has all but disappeared. James Heathers, The Atlantic, 23 Oct. 2021 This three-weekend showcase for boundary-pushing L.A.-based theater, dance and multimedia artists returns for its 18th year. Los Angeles Times, 7 Oct. 2021 These necessary hair-care products build a boundary between your hair and the heat, which staves off breakage, frizz, and all-around damage to the follicle. Leah Prinzivalli, Allure, 5 Oct. 2021 The Western intellectual tradition spent millennia maintaining a conceptual boundary between public and private—embedding it in law and politics, norms and etiquette, theorizing and reinscribing it. Chris Hayes, The New Yorker, 24 Sep. 2021

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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Time Traveler for boundary

Time Traveler

The first known use of boundary was in 1598

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Dictionary Entries Near boundary

bound and gagged


boundary condition

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Statistics for boundary

Last Updated

26 Nov 2021

Cite this Entry

“Boundary.” Dictionary, Merriam-Webster, Accessed 4 Dec. 2021.

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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

More from Merriam-Webster on boundary

Nglish: Translation of boundary for Spanish Speakers

Britannica English: Translation of boundary for Arabic Speakers


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