boundary

noun

bound·​ary ˈbau̇n-d(ə-)rē How to pronounce boundary (audio)
plural boundaries
Synonyms 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
boundaryless
ˈbau̇n-d(ə-)rē-ləs How to pronounce boundary (audio)
adjective
boundarylessness noun

Synonyms of boundary

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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?
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
With fragrance concentrations reaching up to 60 percent, Lumière d’Azur pushes the boundaries of what is possible in perfumery. — Kathryn Hopkins, Footwear News, 13 Oct. 2026 Chew said rapid advances in AI were opening up possibilities far beyond the technology's current applications, even as questions remain over how to ensure increasingly powerful systems operate within human ethical boundaries. — Lee Ying Shan, CNBC, 12 Oct. 2026 The rise in streaming coupled with a desire to push boundaries has seen the nation shift from a more passive importer of formats to one that is setting its agenda on a global stage. — Jesse Whittock, Deadline, 12 Oct. 2026 Comedy is about pushing boundaries, and Gillis is really good at that. — Tony Maglio, HollywoodReporter, 12 Oct. 2026 See All Example Sentences for boundary

Word History

Etymology

bound entry 6 + -ary entry 1

First Known Use

1598, in the meaning defined above

Time Traveler
The first known use of boundary was in 1598

Phrases Containing boundary

Browse Nearby Words

bound and gagged
boundary
boundary condition
See all Nearby Words

Cite this Entry

“Boundary.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/boundary. Accessed 14 Oct. 2026.

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Kids Definition

boundary

noun
bound·​ary ˈbau̇n-d(ə-)rē How to pronounce boundary (audio)
plural boundaries
: something that points out or shows a limit or end : dividing line

Legal Definition

boundary

noun
bound·​ary
plural boundaries
: a theoretical line that marks the limit of an area of land
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