Definition of "quaternary" in English

adjective

1. Of fourth rank or order.

   • the quaternary stress in a pronounced word

2. Of a mathematical expression containing e.g. x⁴.

3. Relating to or in number base four.

4. (organic chemistry) quaternary ammonium.

5. (inorganic chemistry) Composed of four elements.

noun

1. (chemistry) A quaternary compound.

2. (geology) The Quaternary period or the system of deposits laid down during it.