Why this word is great
TETRACTYS — [Noun] A triangular figure of ten points arranged in four rows, representing the fourth triangular number and held as a sacred symbol by the Pythagoreans. From the Ancient Greek τετρακτύς (tetraktús), from τετράς (tetrás, "a set of four") + -τύς (abstract noun suffix). Unlike the tetrahedron, a cold, spatial solid of four faces, or the triad, a mystical but incomplete trilogy, the tetractys is a two-dimensional ladder of ascent, a sacred grammar where one begets two, two begets three, and three begets four, to consummate in the holy decad of ten. It is the pebbles counted in the sand to prove the wholeness of number, the perfect spacing of seeds in a sunflower’s heart, and the austere lattice upon which the cosmos was thought to be strung—a geometry not of space, but of essence, where simplicity begets all complexity.