boundary

[boun-duh-ree, -dree] / ˈbaʊn də ri, -dri /

NOUN

outer limit

Synonyms

STRONGEST

barrier border borderline bounds confines edge frontier horizon line perimeter

STRONG

ambit beginning borderland brink circumference circumscription compass end environs extent extremity frame fringe hem limits march margin mark mere mete outline outpost pale periphery precinct purlieus radius rim side skirt terminal termination terminus verge

WEAK

abuttals line of demarcation

Antonyms

STRONGEST

center inside interior middle

STRONG

opening start

WEAK

minimum

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.

These boundary zones, known as terminators, mark the transition between the planet's permanent day side and permanent night side.

From Science Daily • Jun. 11, 2026

In Rhode Island, a case has been ongoing for three years over a law that moved the boundary of a public beach further inland.

From The Wall Street Journal • Jun. 9, 2026

While South Wales Police was responsible for the original investigation and storage of the evidence tape, a boundary change in 1996 saw Gwent Police assume responsibility for Caerphilly, and Michaela's case.

From BBC • May 23, 2026

The boundary at which gaming ends and AI begins has always been blurry.

From MarketWatch • May 23, 2026

Dad told us that zone vras known in physics as the boundary between turbulence and order.

From "The Glass Castle" by Jeannette Walls

Vocabulary lists containing boundary

Human Geography - Middle School

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Human Geography - High School

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Political Geography - Middle School

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