com·mis·sar·y / ˈkäməˌserē/ • n. (pl. -sar·ies) 1. a restaurant in a movie studio, military base, prison, or other institution. ∎  a store that sells food and drink to members of an organization, esp. a large grocery store on a military base.2. a deputy or delegate.DERIVATIVES: com·mis·sar·i·al / ˌkäməˈse(ə)rēəl/ adj.

commissary (eccl.) officer representing another XIV; official having charge (esp.) of supplies XV. — medL. commissārius officer in charge, f. commiss-, pp. stem of L. committere COMMIT; see -ARY.
So commissariat (Sc. law) commissary's court XVII; military department charged with providing supplies XVIII; partly — medL. commissāriātus, partly — F. commissariat; see -ATE 1.