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.

They found that the boundary between ferromagnetic and anti-ferromagnetic behavior in this material is unusually weak.

From Science Daily • Apr. 22, 2026

I press her to say who she means, but it’s the one time she sets a boundary.

From Los Angeles Times • 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

Operation Gold began in the summer of 1954 with the construction of a drab-looking warehouse sitting just over the boundary separating East and West Berlin.

From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau

Vocabulary lists containing boundary

Human Geography - Middle School

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Human Geography - High School

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Political Geography - Middle School

Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!