A Galardonian frock
A frock was a simple article of clothing, such as those worn by Galardonian farmers.
During a mission to the Galar capital planet in 2380, Ensign Brad Boimler lost his uniform to a spider cow, and was offered a frock by a Galardonian farmer. Captain Carol Freeman questioned Boimler on the official report of the mission, noting that it stated he had returned to the ship in an "alien frock" despite his assurance that nothing out of the ordinary happened on the surface. (LD: "Second Contact")
A frock is typically more coat-like than the Galardonian overalls depicted.