Source : Webster's Revised Unabridged Dictionary (1913)

Quillaia bark \Quil*la"ia bark`\ (Bot.)
   The bark of a rosaceous tree ({Quillaja Saponaria}), native
   of Chili. The bark is finely laminated, and very heavy with
   alkaline substances, and is used commonly by the Chilians
   instead of soap. Also called {soap bark}.