disjunction

Etymology

From Old French disjunction, from Latin disjunctio.

noun

1. The act of disjoining; disunion, separation.
2. The state of being disjoined, contrasting, or opposing.
   the disjunction expressed by disjunctive conjunctions, such as but or or
   The disjunction between the despotism the British had been practising in India and the liberal, secular, democratic trends of their domestic politics was too embarrassing to endure indefinitely. September 7 2017, Ferdinand Mount, “Umbrageousness”, in London Review of Books
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).