concave

American  

[kon-keyv, kon-keyv, kon-keyv] / kɒnˈkeɪv, ˈkɒn keɪv, ˈkɒn keɪv /

adjective

1. curved like a segment of the interior of a circle or hollow sphere; hollow and curved.

2. Geometry. (of a polygon) having at least one interior angle greater than 180°.

3. Obsolete. hollow.

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noun

1. a concave surface, part, line, or thing.

2. Machinery. a concave piece, as one against which a drum rotates.

verb (used with object)

concaved, concaving

1. to make concave.

concave British  

/ ˈkɒnkeɪv, kɒnˈkeɪv /

adjective

1. curving inwards

2. physics having one or two surfaces curved or ground in the shape of a section of the interior of a sphere, paraboloid, etc

   a concave lens

3. maths (of a polygon) containing an interior angle greater than 180°

4. an obsolete word for hollow

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verb

1. (tr) to make concave

concave Scientific  

/ kŏn′kāv′ /

1. Curved inward, like the inside of a circle or sphere.

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Other Word Forms

• concavely
  adverb
• concaveness
  noun
• subconcave
  adjective
• subconcavely
  adverb
• subconcaveness
  noun

Etymology

Origin of concave

1375–1425; late Middle English (< Middle French ) < Latin concavus, hollow. See con-, cave

Explanation

Concave describes an inward curve; its opposite, convex, describes a curve that bulges outward. They are used to describe gentle, subtle curves, like the kinds found in mirrors or lenses. A valley is a concave curve, a mountain is a convex curve—you can remember this by thinking that things that vex you tend to stick out, and that caves tend to be holes that go in, like valleys or innie belly buttons. If you want to describe a bowl, you might say there is a large blue spot on the center of the concave side.

Example Sentences

This sculpture, called Concave Room for Bees, is an earthen work of art designed to attract the insects by providing a rich and steady source of nutrition.

From Slate • Jul. 29, 2016

Concave mirrors are used to concentrate the sunlight onto the pipe.

From Textbooks • Aug. 12, 2015

Concave doors swoosh open automatically when eyeball-activated security robots recognize certified employees, and 60-foot metal catwalks connect one side of a massive room to the other.

From The Verge • Aug. 14, 2014

Then, for the first time, resort to Concave Chiselling, and with a broad chisel cut away the corners down to the segments previously described.

From Hand-Craft The Most Reliable Basis of Technical Education in Schools and Classes by Sutcliffe, John D.

Natural size. a = Convex surface. b = Concave surface.

From Manual of Surgery Volume First: General Surgery. Sixth Edition. by Thomson, Alexis