Gua″ia‐cum (?), n. [NL., fr. Sp. guayaco, from native name in Hayti.] 1. (Bot.) A genus of small, crooked trees, growing in tropical America.
2. The heart wood or the resin of the Guaiacum officinale or lignum-vitæ, a large tree of the West Indies and Central America. It is much used in medicine. [Written also guaiac.]