A quincunx originally meant a 5/12 fraction of something, but most modern uses involve patterns of five points. "Quincunx" or "quincuncial" may in particular refer to
Derived from original meaning Quincunx (Roman coin), a bronze coin with the value of 5/12 of an as Quincunx (astrology), an angle of 150°, 5/12 of a complete circle
Geometric patterns of points Quincunx, five points, four in a square with one more in the middle of the square. An orchard planted in a square lattice aligned diagonally to the surrounding plot of land Quincunx matrix, a 2×2 Hadamard matrix that generates points in a diagonal lattice pattern Bean machine, also called a quincunx, a machine designed by Sir Francis Galton to demonstrate normal distributions, consisting of an array of pins in a diagonal lattice pattern Quincuncial map, a method of mapping the globe onto a square so that the poles map to the five points of a quincunx Place des Quinconces, a city square in Bordeaux, France, named for the quincunx pattern in which its trees were planted Rhombic lattice, the points of intersection of two families of equally spaced parallel lines, called a quincunx in 19th-century mathematics
Literature The Garden of Cyrus or The Quincunciall Lozenge, 1658 philosophical treatise by Sir Thomas Browne involving the quincunx pattern Mistress Masham's Repose, 1946 novel by T. H. White in which a lake is called the Quincunx The Quincunx of Time, 1973 science fiction novel by James Blish The Avignon Quintet, five novels described by their author, Lawrence Durrell, as forming a quincunx The Quincunx, 1989 novel by Charles Palliser that traces five generations of five families The Quincunx Cycle, series of novels begun in 2014 by Canadian author André Alexis
Biology Quincuncial aestivation, an arrangement of five parts of a flower bud prior to opening found in some plants Quincuncina, a genus of freshwater mussels named for the pattern of nodules on its shells