Meaning of tetrabasic

tet•ra•ba•sic

Pronunciation: (te"tru-bā'sik), [key]
— adj. Chem.
  1. (of an acid) having four atoms of hydrogen replaceable by basic atoms or groups.
  2. containing four basic atoms or groups having a valence of one.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.