1. An arrangement of things by fives in a square or a rectangle, one being placed at each corner and one in the middle; especially, such an arrangement of trees repeated indefinitely, so as to form a regular group with rows running in various directions.

2. <astronomy> The position of planets when distant from each other five signs, or 150 deg .

3. <botany> A quincuncial arrangement, as of the parts of a flower in aestivation. See Quincuncial.

Origin: L, fr. Quingue five + uncia an ounce. The quincunx was marked by five small spots or balls. See Five, and Ounce the weight.

(01 Mar 1998)