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  • arch
    arch
    noun
  • arch-
    arch-
    a combining form that represents the outcome of archi- in words borrowed through Latin from Greek in the Old English period; it subsequently became a productive form added to nouns of any origin, which thus denote individuals or institutions directing or having authority over others of their class (archbishop; archdiocese; archpriest ). More recently, arch-1 has developed the senses “principal” (archenemy; archrival ) or “prototypical” and thus exemplary or extreme (archconservative ); nouns so formed are almost always pejorative.
  • -arch
    -arch
    a combining form meaning “chief, leader, ruler,” used in the formation of compound words.
  • arch.
    arch.
    abbreviation
    archaic.
  • Arch.
    Arch.
    abbreviation
    Archbishop.
Synonyms

arch

1 American  
[ahrch] / ɑrtʃ /

noun

  1. Architecture.

    1. a curved masonry construction for spanning an opening, consisting of a number of wedgelike stones, bricks, or the like, set with the narrower side toward the opening in such a way that forces on the arch are transmitted as vertical or oblique stresses on either side of the opening.

    2. an upwardly curved construction, as of steel or timber functioning in the manner of a masonry arch.

    3. a doorway, gateway, etc., having a curved head; an archway.

    4. the curved head of an opening, as a doorway.

  2. any overhead curvature resembling an arch.

  3. something bowed or curved; any bowlike part.

    the arch of the foot.

  4. a device inserted in or built into shoes for supporting the arch of the foot.

  5. a dam construction having the form of a barrel vault running vertically with its convex face toward the impounded water.

  6. Glassmaking.

    1. a chamber or opening in a glassmaking furnace.

    2. pot arch.


verb (used with object)

  1. to cover with a vault, or span with an arch.

    the rude bridge that arched the flood.

  2. to throw or make into the shape of an arch or vault; curve.

    The horse arched its neck.

verb (used without object)

  1. to form an arch.

    elms arching over the road.

  2. Nautical. hog.

arch 2 American  
[ahrch] / ɑrtʃ /

adjective

  1. playfully roguish or mischievous.

    an arch smile.

  2. cunning; crafty; sly.


noun

  1. Obsolete. a person who is preeminent; a chief.

arch- 3 American  
  1. a combining form that represents the outcome of archi- in words borrowed through Latin from Greek in the Old English period; it subsequently became a productive form added to nouns of any origin, which thus denote individuals or institutions directing or having authority over others of their class (archbishop; archdiocese; archpriest ). More recently, arch-1 has developed the senses “principal” (archenemy; archrival ) or “prototypical” and thus exemplary or extreme (archconservative ); nouns so formed are almost always pejorative.


arch- 4 American  
  1. variant of archi- before a vowel.

    archangel; archenteron.


-arch 5 American  
  1. a combining form meaning “chief, leader, ruler,” used in the formation of compound words.

    monarch; matriarch; heresiarch.


arch. 6 American  

abbreviation

  1. archaic.

  2. archaism.

  3. archery.

  4. archipelago.

  5. architect.

  6. architectural.

  7. architecture.

  8. archive; archives.


Arch. 7 American  

abbreviation

  1. Archbishop.


arch. 1 British  

abbreviation

  1. archaic

  2. archaism

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

-arch 2 British  

combining form

  1. leader; ruler; chief

    patriarch

    monarch

    heresiarch

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

arch 3 British  
/ ɑːtʃ /

adjective

  1. (prenominal) chief; principal; leading

    his arch rival

  2. (prenominal) very experienced; expert

    an arch criminal

  3. knowing or superior

  4. playfully or affectedly roguish or mischievous

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

arch- 4 British  

combining form

  1. chief; principal; of highest rank

    archangel

    archbishop

    archduke

  2. eminent above all others of the same kind; extreme

    archenemy

    archfiend

    archfool

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

arch 5 British  
/ ɑːtʃ /

noun

  1. a curved structure, normally in the vertical plane, that spans an opening

  2. Also called: archway.  a structure in the form of an arch that serves as a gateway

  3. something curved like an arch

    1. any of various parts or structures of the body having a curved or archlike outline, such as the transverse portion of the aorta ( arch of the aorta ) or the raised bony vault formed by the tarsal and metatarsal bones ( arch of the foot )

    2. one of the basic patterns of the human fingerprint, formed by several curved ridges one above the other Compare loop 1 whorl

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. (tr) to span (an opening) with an arch

  2. to form or cause to form an arch or a curve resembling that of an arch

    the cat arched its back

  3. (tr) to span or extend over

    the bridge arched the flooded stream

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
arch Cultural  
  1. In architecture, a curved or pointed opening that spans a doorway, window, or other space.


Usage

What does -arch mean? The combining form -arch is used like a suffix meaning “chief, leader, or ruler.” It is often used in technical terms, especially in sociology. The form -arch comes from Greek árchos, meaning “leader,” and shares a root with the combining form archi-, meaning "first, principal." Discover why at our entry for archi-. What are variants of -arch?While -arch doesn't have any variants, it is related to the form -archy, as in matriarchy. Want to know more? Read our Words That Use -archy article.

Discover More

The form of arch used in building often serves to distinguish styles of architecture from one another. For example, Romanesque architecture usually employs a round arch, and Gothic architecture, a pointed arch.

Other Word Forms

Etymology

Origin of arch1

First recorded in 1250–1300; Middle English arch(e), from Old French arche, from Vulgar Latin arca (unrecorded), feminine variant of Latin arcus arc

Origin of arch2

First recorded in 1680–90; independent use of arch- 1

Origin of arch-3

Middle English; Old English arce-, ærce-, erce- (> Old Norse erki- ) < Latin archi- < Greek ( see archi-); but Dutch aarts-, Middle Low German erse-, Middle High German, German Erz- < Medieval Latin arci-, and Gothic ark- directly < Greek. Cf. archangel

Origin of -arch5

< Greek -archos or -archēs, as comb. forms of árchos leader; cf. archi-

Explanation

An arch is a shape that resembles an upside down "U." You may find this shape in a carefully tweezed eyebrow or in the famous golden pair that make you hunger for a Big Mac. In architecture, an arch is an opening that is often found supporting the weight of a something above it — like a bridge or a wall. In downtown St. Louis, you can visit the Gateway Arch — a freestanding catenary arch that is 630 feet tall and 630 feet wide. As a verb, arch means to make an arch-like shape. "She stretched her back by arching it into a backbend." As an adjective, arch can describe something mischievous or sly: "He teased his friend with an arch comment about his shyness around girls."

Keep Reading on Vocabulary.com

Vocabulary lists containing arch

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Earlier Princess Anne attended a dawn service at Wellington Arch in London which was organised by the New Zealand and Australian high commissions.

From BBC • Apr. 25, 2026

University of Texas quarterback Arch Manning has an NIL valuation of $5.4 million, for example, and Ohio State wide receiver Jeremiah Smith has an NIL value of $4.2 million, according to database On3.

From MarketWatch • Apr. 23, 2026

He tore down the East Wing to make room for a massive ballroom, and he has submitted plans to build a giant Triumphal Arch.

From Salon • Mar. 29, 2026

Protesters carrying placards with slogans like "no to racism" and "you cannot divide us" marched from near Marble Arch to Whitehall near the UK parliament for a planned rally.

From Barron's • Mar. 28, 2026

They drove under the Arch and turned east, twenty bulky, quiet-running, barge-like trucks on caterpillar treads, going single file down the deep streets of Erhenrang through the shadows of morning.

From "The Left Hand of Darkness" by Ursula K. Le Guin