RhymeZone: quadrivalent definitions

Definitions of quadrivalent:

adjective: (chemistry) Having a valence of four
adjective: (of a vaccine) Protecting against four different (usually flu) viruses.
adjective: (graph theory) Said of a graph: that all of its vertices have degree four.
noun: (genetics) Any quadrivalent chromosome

(Definitions from Wiktionary)