Counterfeit

Etymology

From Old French "contrefait", past participle of "contrefaire" (to imitate), from Latin "contra" (against) and "facere" (to make). The literal sense is "made in opposition to" the original — a making that competes with the real thing rather than honoring it.

noun · /KOWN-tur-fit/
An imitation made to pass as the genuine article in order to deceive.
What it names
It isolates the crucial ingredient of a fake — intent to deceive about origin — which separates it from honest copies.
Example
The watch kept perfect time; only the misaligned logo betrayed it as a counterfeit.
Related idea
A counterfeit fakes the identity of a specific genuine thing; an ersatz substitute merely stands in for something better without pretending to be it, and is honest about being second-best.
verb · /KOWN-tur-fit/
To imitate something fraudulently so the fake can be passed off as genuine.
What it names
the act of forging a convincing fake
Example
They were caught counterfeiting hundred-dollar bills on a press in the basement.
Related idea
The counterfeiter and the charlatan both trade on borrowed authenticity — one fakes the object, the other fakes the expertise.