Dibasic \Di*ba"sic\, a. [Pref. di- + basic.]

(Chem.) Having two acid hydrogen atoms capable of replacement by basic atoms or radicals, in forming salts; bibasic; -- said of acids, as oxalic or sulphuric acids. Cf. Diacid, Bibasic.

Note: In the case of certain acids dibasic and divalent are not synonymous; as, tartaric acid is tetravalent and dibasic, lactic acid is divalent but monobasic.

Source: Webster's Revised Unabridged Dictionary (1913)