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. To forge (a metaphorical expression, borrowed from the occupation of the smith) means, properly speaking, no more than to make or form, but in our law it is always taken in an evil sense. 2 East, P. C. p. 852, c. 19,
FORGE
TheLaw.com Law Dictionary & Black's Law Dictionary 2nd Ed.