boundary

[ boun-duh-ree, -dree ]

noun

, plural bound·a·ries.

1. 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.

   Synonyms: limit, bound

2. 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.

3. 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.
4. 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. Compare six ( def 5 ).

boundary

/ -drɪ; ˈbaʊndərɪ /

noun

1. something that indicates the farthest limit, as of an area; border
2. cricket
   1. the marked limit of the playing area
   2. a stroke that hits the ball beyond this limit
   3. the four runs scored with such a stroke, or the six runs if the ball crosses the boundary without touching the ground

Other Words From

• trans·bound·a·ry adjective

Word History and Origins

Origin of boundary¹

First recorded in 1620–30; bound ³ + -ary

Synonym Study

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.

Example Sentences

It’s not the first well-funded social media app to push the boundaries of data privacy.

From Vox

More than a healthy workplaceFlexibility extends beyond the boundaries of the physical work environment.

From Digiday

Creators will inevitably try to push the boundaries of what these humans look like.

From Popular-Science

Redistricting – the once-a-decade process of redrawing political boundaries – is a complex undertaking, laden with jargon and acronyms that can confuse even most political observers.

From Voice of San Diego

This year, we can expect to see a newly energized community of developers working across the boundaries of companies, states and countries to take on some of the world’s biggest problems.

From TechCrunch

First you have to convince people to accept your version of the boundary between law and politics.

From The Daily Beast

We need to take a razor and make a boundary in the shaving foam, people.

From The Daily Beast

In the new paper, Laniakea is defined by a gravitational boundary.

From The Daily Beast

We also need to cross the boundary between environmental and non-environmental issues.

From The Daily Beast

The real Watson was a sociopathic landowner in southwest Florida where land and water know no fixed boundary.

From The Daily Beast

Nearly all the mutineers swung round and galloped headlong for the landward boundary of the paddy field.

From Project Gutenberg

Boundary line between New York and Massachusetts agreed upon.

From Project Gutenberg

Now they are approaching the long row of noble beeches that line the boundary of Mortlake.

From Project Gutenberg

As the car rolled on toward Manhattan's northern boundary, the woman with the green eyes switched on the radio on the dash.

From Project Gutenberg

A large stone set in a secure place surely is a better boundary than a wayward stream whose course is changed by every freshet.

From Project Gutenberg

Related Words

• barrier
• border
• borderline
• bounds
• confines
• edge
• frontier
• horizon
• line
• perimeter