1.nounA bitter balsamic resin or resinous exudation obtained from tropical American trees of the family Burseraceae (Bursera tomentosa and Icica tacamahaca), from East Indian trees of the genus Calophyllum or from the balsam poplar (Populus balsamifera).
2.nounAny tree yielding tacamahac resin, especially, in North America, the balsam poplar or balm of Gilead (Populus balsamifera).