a. Chem. [f. TETRA- + BASIC.] Of an acid: Containing four atoms of hydrogen replaceable by more electropositive elements or radicals. Of a salt: Derived from such an acid.
1863–72. Watts, Dict. Chem., I. 459. Modes of distinguishing between monobasic, dibasic, tribasic, and tetrabasic acids.
1869. Roscoe, Elem. Chem., xv. 154. Pyrophosphoric Acid … H4P2O7…. This acid is tetrabasic, the four atoms of hydrogen being replaceable, either all or in part, by metals.
