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.

This remarkable effect occurs at a special condition known as the "Dirac point," where graphene sits at a boundary between being a metal and an insulator.

From Science Daily • Apr. 15, 2026

First, the fact that she felt a vested interest in how much money he gives to his kids crosses a boundary that would make most people uncomfortable.

From MarketWatch • Apr. 13, 2026

Maritime experts have said there is no legal argument for why Iran would be able to regulate commercial shipping on Oman’s side of the maritime boundary.

From The Wall Street Journal • Apr. 8, 2026

There was a crater, he said, on the nearside-farside boundary - a bright spot to the northwest of Glushko crater.

From BBC • Apr. 7, 2026

Brandon stood on the white boundary line, away from her.

From "The Parker Inheritance" by Varian Johnson

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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