An Etymological Dictionary of Astronomy and Astrophysics

The univalent radical or group consisting of one hydrogen and one oxygen atom, forming a part of a molecule of a compound.

See also: From → hydro- + ox(y)- a combining form meaning “sharp, acute, pointed, acid,” used in the formation of compound words, from Gk, oxys “sharp, keen, acid” + -yl a suffix used in the names of chemical radicals, from Fr. -yle, from Gk. hyle “matter, substance;” → group.