Answer: TETRAD

AnswerCrossword Clue
TETRADQuaternion.
tetradgroup of four
tetradtetravalent or quadrivalent element, atom, or group
tetradgroup of four chromatids formed by synapsis at the beginning of meiosis
tetrada group of four
tetradthe number four
TETRADGift of calling birds, say
TETRADThe Horsemen of the Apocalypse, e.g.
TETRADTrio plus one
TETRADGolf group often
TETRADHalf of an octet
TETRADCat's paws, e.g.
TETRADThe women in "Little Women," e.g.
TETRADFourfold
TETRADChord.
TETRADFoursome
TETRADGroup of four.
TETRADFour.
TETRADCollection of four.
TETRADThe number four.
TETRADBrahms' symphonies, e.g.
TETRADThe classical elements, e.g.
TETRADFour of a kind
TETRADGroup of four
TETRADFour-note chord
TETRADMonopoly's railroads, e.g.
TETRADAny foursome
TETRADQuartet
TETRADFour-part structure