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

Example Sentences

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 The primary concern for Thursday is a weakening cold front being pushed across the nation, the boundary of which could be close to the spaceport during the launch window, and could violate cloud and lightning rules. Richard Tribou, Orlando Sentinel, 25 Jan. 2023 That’s the story of Moore, whose boundary-breaking ticket included Aruna Miller, the first woman of color and first immigrant elevated to lieutenant governor in state history. Petula Dvorak, Washington Post, 19 Jan. 2023 That’s weird because the boundary is only two dimensional while the universe is three-dimensional. The Physics Arxiv Blog, Discover Magazine, 5 Dec. 2022 The northern boundary is below the base and includes part of northern Pulaski county. Michael R. Wickline, Arkansas Online, 18 Sep. 2022 No matter the boundary or criterion, a Nancy Stella Soto design is unmistakable. Natalie Meade, Los Angeles Times, 14 Sep. 2022 The boundary between cooler and warmer air will be close by, leaving us with clouds and showers. Dave Epstein,, 2 Sep. 2022 Some of the world cinema’s greatest directors counted Godard’s boundary-breaking work as an influence, including Quentin Tarantino, Bernardo Bertolucci, Brian De Palma and Jonathan Demme. Dallas News, 13 Sep. 2022 Its northern boundary is less than a half-mile south of Huntsville Brownsferry Road – also known as the exit where the new Buc-ee’s in Athens is located – and the southern border is near Ingram Road. Paul Gattis |, al, 16 Dec. 2022 See More

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.

Word History

First Known Use

1598, in the meaning defined above

Time Traveler
The first known use of boundary was in 1598

Dictionary Entries Near boundary

Cite this Entry

“Boundary.” Dictionary, Merriam-Webster, Accessed 7 Feb. 2023.

Kids Definition


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


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

More from Merriam-Webster on boundary

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