boundary
Americannoun
plural
boundaries-
a line or limit where one thing ends and another begins, or something that indicates such a line or limit.
The ancient wall still serves as the city's outer boundary.
These studies straddle the boundaries between computational and social sciences.
-
a limit that separates acceptable behavior from unacceptable behavior.
I'm just looking for a partner who can respect my boundaries.
Guiding children toward responsible money habits requires setting boundaries.
-
Also called frontier. Mathematics. the collection of all points of a given set having the property that every neighborhood of each point contains points in the set and in the complement of the set.
-
Cricket. a hit in which the ball reaches or crosses the boundary line of the field on one or more bounces, counting four runs for the batsman.
noun
-
something that indicates the farthest limit, as of an area; border
-
cricket
-
the marked limit of the playing area
-
a stroke that hits the ball beyond this limit
-
the four runs scored with such a stroke, or the six runs if the ball crosses the boundary without touching the ground
-
Related Words
Boundary, border, frontier share the sense of that which divides one entity or political unit from another. Boundary, in reference to a country, city, state, territory, or the like, most often designates a line on a map: boundaries are shown in red. Occasionally, it also refers to a physical feature that marks the agreed-upon line separating two political units: The Niagara River forms part of the boundary between the United States and Canada. Border is more often used than boundary in direct reference to a political dividing line; it may also refer to the region (of, for instance, a country) adjoining the actual line of demarcation: crossing the Mexican border; border towns along the Rio Grande. Frontier may refer to a political dividing line: crossed the Spanish frontier on Tuesday. It may also denote or describe the portion of a country adjoining its border with another country ( towns in the Polish frontier ) or, especially in North America, the most remote settled or occupied parts of a country: the frontier towns of the Great Plains. Frontier, especially in the plural, also refers to the most advanced or newest activities in an area of knowledge or practice: the frontiers of nuclear medicine.
Other Word Forms
- transboundary adjective
Etymology
Origin of boundary
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Unless the stock can get firmly above the upper boundary of the resistance zone, which comes in around $298, the key downside level to watch is the March 12 intraday low of around $279.
From MarketWatch • Mar. 31, 2026
All five councils affected by the park's proposed boundary said they had reservations, with several issuing a formal objection.
From BBC • Mar. 26, 2026
“We want people to feel unease, but I don’t want anyone taken out of the story because a boundary or line was crossed,” Millet says.
From Los Angeles Times • Mar. 26, 2026
Strong reflections at the air-dielectric boundary keep the light circulating inside the cavity.
From Science Daily • Mar. 24, 2026
The bad news was that the river destroyed many of the boundary markers, erasing all of the landmarks that told farmers which land was theirs to cultivate.
From "Zero: The Biography of a Dangerous Idea" by Charles Seife
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
