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.

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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.

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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.

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arch- ⁴ American  

1. variant of archi- before a vowel.

   archangel; archenteron.

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-arch ⁵ American  

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

   monarch; matriarch; heresiarch.

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arch. ⁶ American  

abbreviation

1. archaic.

2. archaism.

3. archery.

4. archipelago.

5. architect.

6. architectural.

7. architecture.

8. archive; archives.

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Arch. ⁷ American  

abbreviation

1. Archbishop.

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arch- ¹ 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

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arch ² 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

4. 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

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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

arch. ³ British  

abbreviation

1. archaic

2. archaism

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-arch ⁴ British  

combining form

1. leader; ruler; chief

   patriarch

   monarch

   heresiarch

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arch ⁵ 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

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arch Cultural  

1. In architecture, a curved or pointed opening that spans a doorway, window, or other space.

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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

• archly adverb
• archness noun

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 ( archi- ); but Dutch aarts-, Middle Low German erse-, Middle High German, German Erz- < Medieval Latin arci-, and Gothic ark- directly < Greek. archangel

Origin of -arch⁵

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

Example Sentences

US President Donald Trump's administration on Friday revealed renderings for a colossal triumphal arch proposed for construction in Washington near some of the nation's most revered monuments.

From Barron's • Apr. 11, 2026

The renderings of the arch depict gold inscription that say "One Nation Under God", topped with two gold eagles and a golden-winged Lady Liberty.

From BBC • Apr. 10, 2026

You’re going to want to consume a lot of instant ramen doused with soy sauce so the sodium gives you moonface, hiding any hint of a zygomatic arch.

From The Wall Street Journal • Apr. 5, 2026

We can see Houghton’s play in these moments, but then Alloway’s cheeky pop sensibility intervenes, the arch artificiality and ironic tone draining the emotional impact.

From Los Angeles Times • Mar. 26, 2026

Bracing himself against a stone arch, Matthias pulled the sparrow back to safety.

From "Redwall" by Brian Jacques

Related Words

• arc
• archway