• Webster's Revised Unabridged Dictionary
    • a Quadrivalent (Chem) Having a valence of four; capable of combining with, being replaced by, or compared with, four monad atoms; tetravalent; -- said of certain atoms and radicals; thus, carbon and silicon are quadrivalent elements.
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Century Dictionary and Cyclopedia
    • quadrivalent In chem., noting an atom the equivalence of which is four, or an element one atom of which is equivalent, in combining power, to four atoms of hydrogen; tetradic; tetratomic.
    • n quadrivalent A quadrivalent atom or element.
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Webster's Revised Unabridged Dictionary
Quadri-, + L. valens, -entis, p. pr. See Valence


In news:

Physicians have more research to help them reassure patients and families of the safety of the quadrivalent human papillomavirus vaccine.
A study of girls and young women suggests the quadrivalent human papillomavirus vaccine appeared to be associated with fainting , US researchers say.
FDA Clears MedImmune's FluMist Quadrivalent Flu Vaccine.