1. (noun)
tarweed
- any of various resinous glandular plants of the genus Madia; of western North and South America Synonyms: rosinweed, gum plant, gumweed
2. (noun)
gumweed, gum plant, tarweed, rosinweed
- any of various western American plants of the genus Grindelia having resinous leaves and stems formerly used medicinally; often poisonous to livestock Synonyms: rosinweed, gum plant, gumweed, tarweed