TRIVALENT
trivalent
(adjective) having a valence of three
Source: WordNet® 3.1
Etymology
Adjective
trivalent (not comparable)
(inorganic chemistry) Having a valence of three.
(of a vaccine) Protecting against three different (usually flu) viruses.
Noun
trivalent (plural trivalents)
(genetics) Any trivalent chromosome
Source: Wiktionary
Triv"a*lent, a. Etym: [Pref. tri- + L. valens, -entis, p. pr. See
Valence.] (Chem.)
Definition: Having a valence of three; capable of being combined with,
substituted for, or compared with, three atoms of hydrogen; -- said
of triad atoms or radicals; thus, nitrogen is trivalent in ammonia.
Source: Webster’s Unabridged Dictionary 1913 Edition