1. Any of several Old World plants of the genus Chrysanthemum, such as C. coccineum, cultivated for their showy flower heads.
2. An insecticide made from the dried flower heads of Chrysanthemum cinerariifolium or C. coccineum.

[Latin, pellitory, from Greek purethron, feverfew, from pūr, fire (from its warming effect). See pyretic.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.