See under wormseed(def 1).
the dried, unexpanded flower heads of a wormwood, Artemisia cina (Levant wormseed), or the fruit of certain goosefoots, especially Chenopodium anthelminticum (or C. ambrosioides), the Mexican tea or American wormseed, used as an anthelmintic drug.
any of these plants.
Origin of wormseed
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
any of various plants having seeds or other parts used in medicine to treat worm infestation, esp an American chenopodiaceous plant, Chenopodium anthelminticum (or C. ambrosioides) (American wormseed), and the santonica plant
the part of any of these plants that is used as an anthelmintic
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012