CONCHOID

Etymology

Noun

conchoid (plural conchoids)

(mathematics, geometry) Any of a family of curves defined as the locus of points p, such that each p is on a line that passes through a given fixed point P and intersects a given curve, C, and the distance from p to the point of intersection with C is a specified constant (note that for nontrivial cases two such points p satisfy the criteria, and the resultant curve has two parts).

(geology) A conchoidal fracture in rock.

Usage notes

The fixed point (P) of the construction may be referred to as the focus of the conchoid; it may also be defined as the origin (of a Cartesian coordinate system) or the pole (if polar coordinates are used), and potentially referred to accordingly. The curve C is an example of a directrix.

Source: Wiktionary


Con"choid, n. Etym: [Gr. conchoĂŻde.] (Geom.)

Definition: A curve, of the fourth degree, first made use of by the Greek geometer, Nicomedes, who invented it for the purpose of trisecting an angle and duplicating the cube.

Source: Webster’s Unabridged Dictionary 1913 Edition



RESET




Word of the Day

2 April 2025

COVERT

(adjective) secret or hidden; not openly practiced or engaged in or shown or avowed; “covert actions by the CIA”; “covert funding for the rebels”


coffee icon

Coffee Trivia

Contrary to popular belief, coffee beans are not technically beans. They are referred to as such because of their resemblance to legumes. A coffee bean is a seed of the Coffea plant and the source for coffee. It is the pit inside the red or purple fruit, often referred to as a cherry. Just like ordinary cherries, the coffee fruit is also a so-called stone fruit.

coffee icon