Cascarilla \Cas`ca*ril"la\, n.[Sp., small thin bark, Peruvian bark, dim. of c['a]scara bark.]

(Bot.) A euphorbiaceous West Indian shrub (Croton Eleutheria); also, its aromatic bark.

Cascarilla bark (or Cascarilla) (Med.), the bark of Croton Eleutheria. It has an aromatic odor and a warm, spicy, bitter taste, and when burnt emits a musky odor. It is used as a gentle tonic, and sometimes, for the sake of its fragrance, mixed with smoking tobacco, when it is said to occasion vertigo and intoxication.

Source: Webster's Revised Unabridged Dictionary (1913)