A chief linguistics officer was an officer in charge of all linguistic sciences aboard a starship, starbase or space station. Starfleet utilized linguistic officers in unexplored or under-explored areas of space where many first contact situations might arise.
Exploring the Typhon Expanse and regions around it where many various cultures and species existed, the USS Cantabrian (NCC-24705) had a chief linguistics officer named Threk. After Threk's untimely death in 2372, Captain Noah Wrightson promoted Lieutenant junior grade Benjamin Caldwell to chief linguistics officer of the Cantabrian. (Star Trek: The Cantabrian Expeditions: "Catalyst, Part Two")