Meaning of quinquevalent

quin•que•va•lent

Pronunciation: (kwing"kwu-vā'lunt, kwin"-, kwin-kwev'u-lunt, kwing-), [key]
— adj. Chem.
  1. pentavalent.
  2. exhibiting five valences, as phosphorus with valences 5, 4, 3, 1, and −3.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.