A Disjunction

1. The act of disjoining; disunion, separation.
2. The state of being disjoined.
3. (logic) The proposition resulting from the combination of two or more propositions using the or operator.
4. (mathematics) A logical operator that results in “true” when some of its operands are true.
5. (biology) During meiosis, the separation of chromosomes (homologous in meiosis I, and sister chromatids in meiosis II).