Cas"sock (?), n. [F. casaque, fr. It. casacca, perh. fr. L. casa cottage, in It., house; or of Slavic origin.]
A long outer garment formerly worn by men and women, as well as by soldiers as part of their uniform.
A garment resembling a long frock coat worn by the clergy of certain churches when officiating, and by others as the usually outer garment.
© Webster 1913.