Definition of Forge
To fabricate by false imitation. Carter v. State, 135 Tex.Cr.R. 457, 116 S.W.2d 371, 377. To fabricate, construct, or prepare one thing in imitation of another thing, with the intention of substituting the false for the genuine, or otherwise deceiving and defrauding by the use of the spurious article. To counterfeit or make falsely. Especially, to make a spurious written instrument with the intention of fraudulently substituting it for another, or of passing it off as genuine; or to fraudulently alter a genuine instrument to another’s prejudice; or to sign another person’s name to a document, with a deceitful and fraudulent intent. See Counterfeiter; Forgery; Fraud.
That's the definition of Forge in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.