Log"wood` (?) n. [So called from being imported in logs.] The heartwood of a tree (Hæmatoxylon Campechianum), a native of South America, It is a red, heavy wood, containing a crystalline substance called hæmatoxylin, and is used largely in dyeing. An extract from this wood is used in medicine as an astringent. Also called Campeachy wood, and bloodwood.