Brewer's: OEil de Boeuf
(L'). A large reception-room (salle) in the palace of Versailles, lighted by round windows so called. The ceiling, decorated by Van der Meulen, contained likenesses of the children of Louis XIV.
(seventeenth and eighteenth centuries).
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894