\Ptis"an\, n. [L. ptisana peeled barley, barley water,
Gr. ?, from ? to peel, husk; cf. F. ptisane, tisane.]
1. A decoction of barley with other ingredients; a
   farinaceous drink.
2. (Med.) An aqueous medicine, containing little, if any,
   medicinal agent; a tea or tisane.