perpendicular
C1Formal, Technical, Academic
Definition
Meaning
At an angle of 90° to a given line, plane, or surface; forming a right angle.
Extending or pointing straight up or down; vertical. Also used figuratively to describe something extremely steep, upright, or independent in stance.
Linguistics
Semantic Notes
Primarily a geometric and spatial term. In figurative use, it often connotes rigidity, uprightness, or independence. Can describe both physical orientation and abstract relationships.
Dialectal Variation
British vs American Usage
Differences
No significant differences in core meaning. In architecture, 'Perpendicular' (capitalized) specifically refers to the late English Gothic style (14th–16th centuries), a usage more common in UK historical contexts.
Connotations
Similar connotations of precision, exactness, and uprightness in both varieties.
Frequency
Slightly higher frequency in UK English due to the architectural/historical reference. In general technical use, frequency is comparable.
Vocabulary
Collocations
Grammar
Valency Patterns
be perpendicular to [NOUN PHRASE]draw a line perpendicular from [POINT] to [LINE]stand perpendicular (to the ground)Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “The Perpendicular Style (architecture)”
- “drop a perpendicular (geometry)”
Usage
Context Usage
Business
Rare. Might appear in technical project descriptions involving design or construction.
Academic
Common in mathematics, geometry, physics, engineering, and architecture.
Everyday
Used to describe very steep slopes or things standing straight up (e.g., a cliff).
Technical
Core term in geometry, drafting, construction, and physics to denote a 90-degree relationship.
Examples
By Part of Speech
verb
British English
- The architect instructed us to perpendicular the new wall from the existing one.
- The surveyor will perpendicular the boundary line from the datum point.
American English
- The engineer had us perpendicular the support beam from the foundation.
- You need to perpendicular the plumb line from the ceiling joist.
Examples
By CEFR Level
- The teacher drew two perpendicular lines on the board to make a plus sign.
- The lamp post stands perpendicular to the pavement.
- For the shelf to be stable, it must be fixed perpendicular to the wall.
- The path ended at a perpendicular cliff face.
- In geometry, the sine of an angle in a right triangle is the length of the side opposite the angle divided by the length of the hypotenuse, but only if the triangle's sides are perpendicular.
- His political views were often perpendicular to the mainstream party line.
- The geologist noted the strata were folded, with newer layers lying perpendicular to the orientation of the bedrock.
- The novel's narrative structure is deliberately perpendicular to chronological storytelling, creating a disorienting but powerful effect.
Learning
Memory Aids
Mnemonic
Think of a 'pendulum' hanging straight DOWN. 'Per-pend-icular' lines are like the string of a pendulum relative to the ground – forming a right angle.
Conceptual Metaphor
MORAL UPRIGHTNESS IS PHYSICAL UPRIGHTNESS (e.g., 'a man of perpendicular integrity'). INDEPENDENCE IS BEING PERPENDICULAR (not parallel/conforming).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid confusing with 'перпендикулярный', which is a direct cognate but used almost exclusively in geometric/technical contexts. The figurative 'upright' sense is less common in Russian.
- Do not use 'перпендикулярно' for simple 'vertically' ('вертикально').
Common Mistakes
- Using 'perpendicular' as a synonym for 'vertical' in all contexts (vertical is a specific case of perpendicular relative to the horizon).
- Confusing 'perpendicular' (90°) with 'parallel' (0°).
- Misspelling as 'perpendiculaur' or 'perpendiculer'.
Practice
Quiz
In which context is 'Perpendicular' (capitalized) a proper noun with a specific historical meaning?
FAQ
Frequently Asked Questions
'Vertical' specifically means aligned with the direction of gravity (up-down relative to the earth). 'Perpendicular' means at a 90-degree angle to any given reference line or plane. A line can be perpendicular to a slanted surface without being vertical.
Yes, especially in geometry. E.g., 'Drop a perpendicular from point A to line BC' means to draw a line from A that meets BC at a 90-degree angle.
No. While its primary and most precise use is in mathematics and technical fields, it is commonly used in everyday language to describe something very steep or upright, like a 'perpendicular cliff'.
The most common mistake is using it interchangeably with 'parallel'. They are opposites: perpendicular lines intersect at 90°, parallel lines never intersect. Another is overextending it to mean simply 'straight' rather than 'at a right angle'.