perpendicular

1 of 3

adjective

per·​pen·​dic·​u·​lar ˌpər-pən-ˈdi-kyə-lər How to pronounce perpendicular (audio)
Synonyms of perpendicular
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 Perpendicular : 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 How to pronounce perpendicular (audio)
-ˈla-rə-
noun
perpendicularly
ˌpər-pən-ˈdi-kyə-lər-lē How to pronounce perpendicular (audio)
adverb

perpendicular

2 of 3

noun (1)

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

perpendicularity

3 of 3

noun (2)

per·​pen·​dic·​u·​lar·​i·​ty
-rətē, 
-i also -ˈler-
plural -es
: the quality or state of being perpendicular

Synonyms of perpendicular

Relevance

Adjective

See All Synonyms & Antonyms in Thesaurus
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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
Bend your knees and sit back so that your thighs are parallel to the floor, and your shins remain perpendicular. — Sarah Bence, Verywell Health, 8 June 2026 At each of the four end points, a small panel about 2 to 3 feet wide would be mounted perpendicular to the netting to prevent access. — David Garrick, San Diego Union-Tribune, 20 May 2026
Noun
Lay 2 longest strips across center of pie perpendicular to each other. — ABC News, 29 June 2026 The racer is traversing the hill perpendicular to the fall line, almost moving in an upward direction. — Los Angeles Times, 9 Feb. 2026 See All Example Sentences for perpendicular

Word History

Etymology

Adjective

Middle English perpendiculer, borrowed from Middle French & Latin; Middle French perpendiculier, borrowed from Latin perpendiculāris, from perpendiculum "plumb line, vertical line or plane" (from perpendere "to weigh with care, poise, balance carefully" + -i-culum, instrumental suffix —going back to Indo-European *-tlom) + -āris -ar — more at perpend

Noun (1)

derivative of perpendicular entry 1

Noun (2)

Medieval Latin perpendicularitas, from Latin perpendicularis + -itas -ity

First Known Use

Adjective

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

Noun (1)

1551, in the meaning defined above

Time Traveler
The first known use of perpendicular was in the 14th century

Rhymes for perpendicular

See All Rhymes for perpendicular

Browse Nearby Words

perpend
perpendicular
perpendicularity
See all Nearby Words

Cite this Entry

“Perpendicular.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/perpendicular. Accessed 7 Jul. 2026.

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Kids Definition

perpendicular

1 of 2 adjective
per·​pen·​dic·​u·​lar ˌpər-pən-ˈdik-yə-lər How to pronounce perpendicular (audio)
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

More from Merriam-Webster on perpendicular

Nglish: Translation of perpendicular for Spanish Speakers

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