A bitter, aromatic herb used in flavoring absinthe, some wines such as vermouth, and occasionally (but not in the United States) in cooking. In the past, wormwood was popular as a medicinal herb for colds, stomach problems and rheumatism. Because the flavoring oil extracted from this herb is potentially poisonous, the United States has banned preparations (such as absinthe) made with an excessive amount of it. See also herbs.