protoxide

[Pref. prot-, and Eng.oride.] Chem .: When a metal forms more than one oxide, the one containing the least proportion of oxygen is called the protoxide. Protoxide of copper= Melaconite ; protoxide of nickel Bunsenite ; protoxide of zinc= Zincite ; protoxide of lead= Ma icot . prō-tox-i-dize, v . t . [Eng. protoxid (e); -ize.] Chem.: To combine with oxygen, as any elementary substance, in the proportion of one equivalent of oxygen, and one of the other.