counterfeit
This term carries a strong connotation of criminal intent and deception. While words like fake or imitation might describe a cheap version of a product, this word specifically implies a deliberate attempt to pass off a fraud as the original to cheat someone. When used to describe human emotions or behavior, it suggests a calculated performance of sincerity. It describes a facade that is consciously constructed to mislead others about one's true internal state.
Meanings
Made in a fraudulent imitation of something else to deceive people.
"The police seized a large shipment of counterfeit handbags."
False or fake; not genuine in nature or intention.
"He gave a counterfeit smile to hide his true anger."
A fraudulent imitation of something, especially money or a work of art.
"The bank teller quickly identified the twenty-dollar bill as a counterfeit."
To make a fraudulent copy of something in order to deceive.
"The criminals attempted to counterfeit the company's official seal."