Meaning of BOUNDARY in English

bound ‧ a ‧ ry /ˈbaʊnd ə ri/ BrE AmE noun ( plural boundaries )

[ Date: 1600-1700 ; Origin: ⇨ ↑ bound 4 (1) ]

1 . [countable] the real or imaginary line that marks the edge of a state, country etc, or the edge of an area of land that belongs to someone

boundary between

The Mississippi River forms a natural boundary between Iowa and Illinois.

National boundaries are becoming increasingly meaningless in the global economy.

We would need their agreement to build outside the city boundary.

The stream curves round to mark the boundary of his property.

Anything that crosses the boundary of a black hole cannot get back.

We walked through the churchyard towards the boundary wall.

The property’s boundary line is 25 feet from the back of the house.

boundary disputes between neighbouring countries

2 . [countable usually plural] the limit of what is acceptable or thought to be possible

boundary of

the boundaries of human knowledge

within/beyond the boundaries of something

within the boundaries of the law

push back the boundaries (of something) (=to make a new discovery, work of art etc that is very different from what people have known before, and that changes the way they think)

art that pushes back the boundaries

3 . [countable] the point at which one feeling, idea, quality etc stops and another starts

boundary of/between

the boundaries between work and play

the blurring of the boundaries between high and popular culture

4 . [countable] the outer limit of the playing area in ↑ cricket , or a shot that sends the ball across this limit for extra points

• • •


■ ADJECTIVES/NOUN + boundary

▪ national/state boundaries (=boundaries between countries or states)

Big companies usually aim to expand outside national boundaries.

▪ international boundaries (=boundaries between countries all over the world)

About 10% of hazardous waste is shipped across international boundaries.

▪ a city boundary

The new housing estates stretch beyond the old city boundaries.

▪ the northern/southern etc boundary (=of an area or city)

the southern boundary of San Francisco

▪ a geographical boundary

Today satellite communications cross all geographical boundaries.

▪ a political boundary

Reforms could extend the geographical and political boundaries of the EU.

▪ a natural boundary (=a river, line of mountains etc that form a boundary)

Here, the Andes form a natural boundary between Argentina and Chile.

■ verbs

▪ mark/form a boundary

The river Jordan marks the boundary between Israel and Jordan.

▪ cross/transcend a boundary

These are practical problems that cross political boundaries.

■ boundary + NOUN

▪ a boundary wall/fence

The boundary wall was about twenty foot high.

▪ a boundary line

There was some disagreement about the exact position of the boundary line.

▪ a boundary dispute (=a disagreement about where a boundary should be, for example between neighbours)

We had to hire a lawyer to sort out the boundary dispute.

• • •


▪ border the official line that separates two countries, or the area close to this line:

The town lies on the border between Chile and Argentina.


Strasbourg is very close to the German border.


border guards

▪ frontier especially British English the border:

They crossed the Libyan frontier into Egypt.

▪ line the official line that separates states and counties in the US:

His family lived across the state line in West Virginia.

▪ boundary the line that marks the edge of an area of land that someone owns, or one of the parts of a country:

The fence marks the boundary between the two properties.


The Mississippi River forms the boundary between Tennessee and Arkansas.


A road runs along the western boundary of the site.

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.