To counterfeit means to imitate something authentic, with the intent to steal, destroy, or replace the original, for use in illegal transactions, or otherwise to deceive individuals into believing that the fake is of equal or greater value than the real thing.

Excerpt from Eastman's Treatise on Counterfeit, Altered and Spurious Bank Notes: With Unerring Rules for the Detection of Frauds in the Same. Nor can it be regarded as extravagant to say that the whole fabric of society and of national and individual opulence, resting as it does to so great an extent on this metallic and paper basis, will stand securely only so long as confidence exists in the purity and substantiality of that basis.

About Author,

Harvey Gridley Eastman (October 16, 1832 – July 13, 1878) was an American educator and politician from New York.
Born in Marshall, New York, Eastman was the son of Horace Haveland Eastman and Mary A. Gridley. Eastman began his professional career teaching at the Eastman Commercial College in Rochester, New York, which had been founded by his uncle, George Washington Eastman. In December 1855, he founded a school of his own in Oswego. He married Mary Minerva Clark on June 5, 1857.