Webster’s Revised Unabridged Dictionary · 1913
Dibasic
Di·ba′sic (dī·bā′sĭk), 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.
☞ 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.