D defs.my
Entry 1 sense Webster, 1913

Monoxide

/mən-äk'-sīd/ · Mo·nox·ide · IPA /məˈnɒksʌɪd/
01 n. An oxide containing one atom of oxygen in each molecule; as, barium monoxide.
  1. 1.
    An oxide containing one atom of oxygen in each molecule; as, barium monoxide.(Chem.)