tetrad

(tĕtˈrădˌ)

1. A group or set of four.
2. A tetravalent atom, radical, or element.
3. Biology
   a. A four-part structure that forms during the prophase of meiosis and consists of two homologous chromosomes, each composed of two sister chromatids.
   b. Botany A group of four cells, as of spores or pollen grains, formed by division of one mother cell.

Related Forms:

• te·tradˈic adjective