Soutane \Sou`tane"\, n. [F., fr. Sp. sotana, or It. sottana, LL. subtana, fr. L. subtus below, beneath, fr. sub under.]

(Eccl. Costume) A close garnment with straight sleeves, and skirts reaching to the ankles, and buttoned in front from top to bottom; especially, the black garment of this shape worn by the clergy in France and Italy as their daily dress; a cassock.

Source: Webster's Revised Unabridged Dictionary (1913)