Plagiarism
Plagiarism was the act of representing another's work as one's own. Those who did so were called plagiarists.
In 2268, Garth accused the Orion Marta of plagiarizing one of Shakespeare's sonnets. She replied by saying that she wrote it again yesterday. (TOS: "Whom Gods Destroy")
According to Jack, the 15th century poet Singh el Bashir was a plagiarist, which caused him to question, perhaps erroneously, why Julian Bashir had bragged about being a relation of his. The doctor replied that Jack had brought it up. (DS9: "Statistical Probabilities")
In 2381, Risik was criticized for copying the styles of his fellow Orions, making him not a pirate in that instance, but a plagiarist instead. (LD: "Something Borrowed, Something Green")
In 2382, Brad Boimler was accused of plagiarizing his alternate timeline counterpart's vibe after copying many of his qualities and experiences, including a cocktail, in an attempt to emulate him. (LD: "Fully Dilated")