The Collaborative International Dictionary of English v.0.48:

Amadou \Am"a*dou\, n. [F. amadou tinder, prop. lure, bait, fr.
   amadouer to allure, caress, perh. fr. Icel. mata to feed,
   which is akin to E. meat.]
   A spongy, combustible substance, prepared from fungus
   (Boletus and Polyporus) which grows on old trees; German
   tinder; punk. It has been employed as a styptic by surgeons,
   but its common use is as tinder, for which purpose it is
   prepared by soaking it in a strong solution of niter. --Ure.
   [1913 Webster]