- a group of four.
- the number four.
- a group of four chromatids formed by synapsis at the beginning of meiosis.
- a tetravalent or quadrivalent element, atom, or group.
- a group or series of four
- the number four
- a group of four cells formed by meiosis from one diploid cell
- a four-stranded structure, formed during the pachytene stage of meiosis, consisting of paired homologous chromosomes that have each divided into two chromatids
- an element, atom, group, or ion with a valency of four
- a square of 2 × 2 km used in distribution mapping
