A square tiling of the plane.

(mathematics) The formula x=(-b±√)/(2a) for finding roots of the quadratic equation.

(mathematics) Any function whose value is the solution of a quadratic polynomial

A period of 4 years, particularly (historical) the sets of four years in the ancient Egyptian and Greek calendars.

plural of quadratic integer

Relating to a 400th anniversary.

A 400th anniversary.

(nautical) A light, narrow rowing boat, especially one used in competitive rowing, in which a four rowers each have two oars / (rowing, especially in plural) A race in which such craft participate

The next bluff in sequence after a double bluff and a triple bluff

To perform a quadruple bluff