A dunsel was a slang term used in the Federation Standard language to describe an item that was completely useless in Starfleet service. Starfleet Academy tradition assigns this moniker to people or things that serve no purpose. (TNG reference: Star Trek: The Next Generation Technical Manual; TOS novel: Vulcan!)
Commodore Robert Wesley once jokingly called Captain James T. Kirk "Captain Dunsel" after Kirk's vessel the USS Enterprise first successfully tested the M-5 computer, which was designed to take over a captain's role commanding a starship. (TOS episode: "The Ultimate Computer")
Lieutenant Roakn and other members of the Titan crew gave Cadet Zurin Dakal the nickname "Cadet Dunsel", giving him the least important jobs in the science section. Commander Jaza Najem responded by assigning Dakal to the Telemetric observation VISOR to run a probe on a quantum rippling effect, saying "I don't believe in dunsels, Cadet. Never have, never will." (TTN novel: Sword of Damocles)
- The term would appear to be derived from the name of Earth Starfleet captain Roy Dunsel; however, since Dunsel and his crew heroically sacrificed themselves in battle, it is unknown exactly how this happened, since the real Captain Dunsel certainly did serve a purpose.