quaternary >> /ˈkwɑdərˌnɛri/
Definition: [noun] The Quaternary period or the system of deposits laid down during it.
Definition: [adjective] Fourth in order or rank; belonging to the fourth order.
Example: In the more complicated previous model [3-6], higher total R1 concentrations favor higher order quaternary states.
Definition: [adjective] Relating to or denoting the most recent period in the Cenozoic era, following the Tertiary period and comprising the Pleistocene and Holocene epochs (and thus including the present).
Example: Together, the Pleistocene and Holocene make up the Quaternary period, marked by waxing and waning of polar glaciers.
Definition: [adjective] Denoting an ammonium compound containing a cation of the form NR₄⁺, where R represents organic groups or atoms other than hydrogen.
Example: Chatburn and coworkers compared the effectiveness of two concentrations of acetic acid, quaternary ammonium compound, and household detergent against a mixture of P. aeruginosa, S. aureus, and Pseudomonas cepacia.