Merriam-Webster Collegiate Dictionary - guaiacum

 noun  Etymology: New Latin, from Spanish guayaco, from Taino guayacan  Date: 1553  1. any of a genus (Guaiacum) of the caltrop family of tropical American evergreen trees and shrubs having pinnate leaves, usually blue flowers, and capsular fruit  2.  a. the hard greenish-brown wood of a ~ (especially Guaiacum officinale)  b. a resin with a faint balsamic odor that is obtained from the trunk of two ~s (G. officinale and G. sanctum) and often used as a clinical reagent