The Collaborative International Dictionary of English v.0.48:

Tisane \Ti*sane"\, n. [F.] (Med.)
   See Ptisan.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tisane
    n 1: infusion of e.g. dried or fresh flowers or leaves

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "tisane":
   balm, balsam, drops, drug, electuary, elixir, ethical drug,
   generic name, herbs, inhalant, lincture, linctus, materia medica,
   medicament, medication, medicinal, medicinal herbs, medicine,
   mixture, nonprescription drug, officinal, patent medicine,
   pharmacon, physic, powder, preparation, prescription drug,
   proprietary, proprietary medicine, proprietary name, simples,
   syrup, theraputant, vegetable remedies