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

Croft’s work crossed the boundaries of art galleries and cinema, with his exhibitions shown everywhere from New York to Beijing. —Jesse Whittock, Deadline, 18 July 2024

Crooks was seen in video obtained by Pittsburgh ABC affiliate WTAE pacing just beyond the boundaries of the Trump rally at 5:06 p.m., around one hour and five minutes before shots were first fired. —Julia Reinstein, ABC News, 17 July 2024

In addition to these styles, the collection showcases bold hues that push denim’s boundaries while offering more subtle shades like New Obsidian and Onyx Blue. —Sj Studio, Sourcing Journal, 16 July 2024

This communicates certainty so others don’t think your boundaries are negotiable. 2. —Aditi Shrikant, CNBC, 15 July 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