methoxyl--prophetes.ai

methoxyl Chem.
  (mɛˈθɒksɪl)
  [f. methyl) + oxygen) + -yl.]
  A hypothetical radical, CH₃O, analogous to hydroxyl.

1866 Frankland in Jrnl. Chem. Soc. XIX. 376 These radicals may be named hydroxyl, methoxyl, ethoxyl, &c.

Oxford English Dictionary