Tetragram

tet′ra-gram, n. a word of four letters: the Tetragrammaton : ( geom. ) a quadrilateral.— n. Tetragram′mat on , the name JeHoVaH as written with four Hebrew letters, regarded as a mystic symbol: similarly some other sacred word of four letters, as the Latin Deus . [Gr., tetra- , four, gramma , a letter.]