See Also: Tetrad(medicine)
tetrad(dictionary)
Fallot's tetrad(medicine)
narcoleptic tetrad(medicine)
half-tetrad analysis(medicine)

tetrad (iou)



tetrad noun. M17.
[Greek tetrad-, tetras a group of four, the number four: see -AD1.]
A sum, group, or set of four. M17.
A. Stevens A tetrad of distinct elementsearth, air, fire and water.
Chemistry. Orig., a tetravalent element or group. Now, a tetrameric unit within a polymer. M19.
Biology. A group of four cells, spores, pollen-grains, etc. Also, a group of four homologous chromatids formed during meiotic division. L19.
A square block of four 1-kilometre squares within a 10-kilometre square, used as a unit in biological recording. M20.
te'tradic adjective of, pertaining to, or of the nature of a tetrad; spec. (Chemistry, now rare or obsolete) tetravalent L18.
Tetradite noun (Ecclesiastical History) a worshipper of a tetrad, esp. one who believes that there are four persons in the Godhead E18.