1. A bitter balsamic resin obtained from tropical American trees of the genus Elaphrium (E. tomentosum and E. Tacamahaca), and also from East Indian trees of the genus Calophyllum; also, the resinous exhudation of the balsam poplar. 2. (Bot.) Any tree yielding tacamahac resin, especially, in North America, the balsam poplar, or balm of Gilead (Populus balsamifera)....
