quadrant

views updated May 21 2018

quadrant.
1. The fourth part of a circle, hence an object or a street with a plan-form based on a fourth of the circumference of a circle. Quad-rant was the name given to part of Regent Street, London, designed 1813–16 by John Nash, laid out on a plan conforming with that shape. A series of buildings the façades of which form a convex curve is called a quadrant, as opposed to that on a concave curve, called crescent. Quadrants were important in Classical composition as e.g. a means of joining a corps-de-logis to pavilions or wings, as in Palladian compositions (Villa Mocenigo (1544–64) by Palladio and Kedleston, Derbys., as designed by Paine (1757–9) )

2. Medieval term for a quadrangle or quad.

3. Octagonal part of a spire.

4. Quarter-round.

quadrant

views updated May 18 2018

quad·rant / ˈkwädrənt/ • n. technical each of four quarters of a circle. ∎  each of four parts of a plane, sphere, space, or body divided by two lines or planes at right angles: the right upper quadrant of the kidney. ∎ hist. an instrument used for taking angular measurements of altitude in astronomy and navigation, typically consisting of a graduated quarter circle and a sighting mechanism. ∎  a frame fixed to the head of a ship's rudder, to which the steering mechanism is attached. ∎  a panel with slots through which a lever is moved to orient or otherwise control a mechanism.DERIVATIVES: quad·ran·tal / kwäˈdran(t)l/ adj.ORIGIN: late Middle English (denoting the astronomical instrument): from Latin quadrans, quadrant- ‘quarter,’ from quattuor four.

quadrant

views updated May 18 2018

quadrant In plane geometry, a quarter of a circle, bounded by radii at right angles to each other and by the arc of the circle. In analytic geometry, it is one of the four sections of a plane divided by an x axis and a y axis. A quadrant is also a device for measuring angles, based on a 90° scale.

quadrant

views updated May 29 2018

quadrant †fourth part, quarter, now only of a quarter-circle; instrument (of the form of a graduated quarter-circle) used for making angular measurements. XIV. — L. quadrāns, -ant- quarter, orig. of the as; see QUADRI-.