The Collaborative International Dictionary of English v.0.48:

faux \faux\ (f[add]ks), n.; pl. fauces (f[add]"s[=e]z). [L.]
   See Fauces.

WordNet (r) 3.0 (2006):

faux
    adj 1: not genuine or real; being an imitation of the genuine
           article; "it isn't fake anything; it's real synthetic
           fur"; "faux pearls"; "false teeth"; "decorated with
           imitation palm leaves"; "a purse of simulated alligator
           hide" [syn: fake, false, faux, imitation,
           simulated]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

FAUX, French law. A falsification or fraudulent alteration or suppression of
a thing by words, by writings, or by acts without either. Biret, Vocabulaire
des Six Codes.
     2. The crimen falsi of the civil law. Toullier says, "Le faux s'entend
de trois manieres: dans le sons le plus etendre, c'est l'alteration de la
verite, avec ou sans mauvaises intentions; il est a peu pres synonyme de
mensonge; dans un sens moins etendu, c'est l'alteration de la verite,
accompagnee de dol, mutatio veritatis cum dolo facta; enfin, dans le sens
etroit, ou plutot legal du mot, quand il s'agit de savoir si le faux est un
crime, le faux est I'alteration frauduleuse de la verite, dans les
determines et punis par la loi." Tom. 9, n. 188. "Faux may be understood in
three ways: in its most extended sense, it is the alteration of truth, with
or without intention; it is nearly synonymous with lying; in a less extended
sense, it is the alteration of truth, accompanied with fraud, mutatio
veritatis cum dolo facta; and lastly, in a narrow, or rather the legal sense
of the word, when it is a question to know if the faux be a crime, it is the
fraudulent alteration of the truth, in those cases ascertained and punished
by the law." See Crimen Falsi.