boundary

noun

bound·​ary ˈbau̇n-d(ə-)rē 

plural boundaries

: something that indicates or fixes a limit or extent

Those two trees mark the boundary of our property.

the mountain range that forms the country's northern boundary

boundaryless

ˈbau̇n-d(ə-)rē-ləs 

adjective

boundarylessness noun

Synonyms

• bound
• cap
• ceiling
• confines
• end
• extent
• limit
• limitation
• line
• termination

Examples of boundary in a Sentence

Those two trees mark the boundary of our property.

The river forms the country's western boundary.

at the boundary between fact and fiction

You need to set boundaries with your children.

Did he violate the boundaries of the doctor-patient relationship?

Recent Examples on the Web

But as the boundaries between B2B and B2C have blurred, especially after the pandemic, when personal and professional browsing habits converged, those avenues might not be the only or even optimal path to getting one's message to the people who need it. —Cheryl Ragland, Forbes, 18 Dec. 2024

Although your attention and focus are on home and family, the influence of Neptune in your relationship sector could blur the boundaries between you and a significant other. —Valerie Mesa, People.com, 17 Dec. 2024

Set boundaries and expectations upfront Freedom works best with clear limits. —Emily Shiffer, Parents, 17 Dec. 2024

Set boundaries unapologetically and gatekeep your energy. —Dominique Fluker, Essence, 17 Dec. 2024

Word History

Etymology

bound entry 6 + -ary entry 1

First Known Use

1598, in the meaning defined above

Phrases Containing boundary

• boundary layer
• K-T boundary

Kids Definition

boundary

noun

bound·​ary ˈbau̇n-d(ə-)rē 

plural boundaries

: something that points out or shows a limit or end : dividing line

Legal Definition

boundary

noun

bound·​ary

plural boundaries

: a theoretical line that marks the limit of an area of land