An inventor was someone who created or designed new objects of technology.
Data, after having traveled back in time to 1893, claimed that he was an inventor upon being asked by Jack London. London had just agreed to use Data's money to purchase a list of items that Data intended to use to construct a device to detect shifts through time. (TNG: "Time's Arrow")
Dr. Zefram Cochrane was credited as being the inventor of warp drive. (Star Trek: First Contact; ENT: "Broken Bow", "The Expanse", "Daedalus"; TOS: "Metamorphosis"; TNG: "New Ground"; VOY: "Year of Hell", "Homestead")