OEil-de-boeuf \[OE]il`-de-b[oe]uf"\, n.; pl. {[OE]ils-de-b[oe]uf}. [F., lit., eye of an ox.] (Arch.) A circular or oval window; -- generally used of architecture of the 17th and 18th centuries. A famous room in the palace of Versailles bears this name, from the oval window opening into it.