What does "frock" mean?

Frock: A coarse gown worn by monks or friars, and supposed to take the place of all, or nearly all, other garments. It has a hood which can be drawn over the head at pleasure, and is girded by a cord. Frock coat, a body coat for men, usually doublebreasted, the skirts not being in one piece with the body, but sewed on so as to be somewhat full. -- Smock frock. See in the Vocabulary.