tetrad

A group or set of four.

A tetravalent atom, radical, or element.

A four-part structure that forms during the prophase of meiosis and consists of two homologous chromosomes, each composed of two sister chromatids.

A group of four haploid cells, such as spores, formed by meiotic division of one mother cell.

The number four; also, a collection of four things. Also quadrad.

In chem., an atom the equivalence of which is four, or an element one atom of which is equivalent, in saturating power, to four atoms of hydrogen.

In morphology, a quaternary unit of organization resulting from individuation or integration of an aggregate of triads. See triad, dyad.

In cytology, a group of four chromosomes formed by the division of a single chromosome; a quadripartite chromosome.

The number four; a collection of four things; a quaternion.