perpendicular

1 of 2

adjective

per·​pen·​dic·​u·​lar ˌpər-pən-ˈdi-kyə-lər 

1

a

: standing at right angles to the plane of the horizon : exactly upright

b

: being at right angles to a given line or plane

2

: extremely steep : precipitous

3

often capitalized : of or relating to a medieval English Gothic style of architecture in which vertical lines predominate

4

: relating to, uniting, or consisting of individuals of dissimilar type or on different levels

perpendicularity

ˌpər-pən-ˌdi-kyə-ˈler-ə-tē 

-ˈla-rə-

noun

perpendicularly

ˌpər-pən-ˈdi-kyə-lər-lē 

adverb

perpendicular

2 of 2

noun

: a line at right angles to a line or plane (as of the horizon)

Synonyms

Adjective

• erect
• plumb
• raised
• stand-up
• standing
• upright
• upstanding
• vertical

Choose the Right Synonym for perpendicular

vertical, perpendicular, plumb mean being at right angles to a base line.

vertical suggests a line or direction rising straight upward toward a zenith.

the side of the cliff is almost vertical

perpendicular may stress the straightness of a line making a right angle with any other line, not necessarily a horizontal one.

the parallel bars are perpendicular to the support posts

plumb stresses an exact verticality determined (as with a plumb line) by earth's gravity.

make sure that the wall is plumb

Examples of perpendicular in a Sentence

Adjective

She lives on the street that is perpendicular to mine.

river rafters staring awestruck at the canyon's nearly perpendicular cliffs

Recent Examples on the Web

Adjective

Imagine a perpendicular line runs through the center star, then follow it up to the bright, red-looking orb above. —Carlyn Kranking, Smithsonian Magazine, 27 Sep. 2024

What to know about rip current safety Rip currents are strong and narrow flows of water, usually less than 80 feet wide, that flow toward the ocean away from the shoreline at an acute or perpendicular angle, according to the National Oceanic and Atmospheric and Administration. —Melissa Alonso, CNN, 23 June 2024

Noun

Water can return to sea via a rip current, a narrow jet of water moving away from shore perpendicular to the shoreline. —Emily Deletter, USA TODAY, 25 June 2024

Hold the knife perpendicular to the wedge and cut it into ¼-inch-wide pieces. —Karla Walsh, Better Homes & Gardens, 15 Feb. 2024

Word History

Etymology

Adjective

Middle English perpendiculer, from Middle French, from Latin perpendicularis, from perpendiculum plumb line, from per- + pendēre to hang — more at pendant

First Known Use

Adjective

14th century, in the meaning defined at sense 1a

Noun

1551, in the meaning defined above

Kids Definition

perpendicular

1 of 2 adjective

per·​pen·​dic·​u·​lar ˌpər-pən-ˈdik-yə-lər 

1

: exactly vertical or upright

2

: forming a right angle with each other or with a given line or plane

perpendicularly adverb

perpendicular

2 of 2 noun

: a perpendicular line

Etymology

Adjective

Middle English perpendiculer "exactly upright," from early French perpendiculer (same meaning), from Latin perpendicularis (same meaning), derived from per- "thoroughly" and pendēre "to hang" — related to depend, pendulum