Pellitory \Pel"li*to*ry\, n. [Sp. pelitre, fr. L. pyrethrum. See {Bertram}.] (Bot.) (a) A composite plant ({Anacyclus Pyrethrum}) of the Mediterranean region, having finely divided leaves and whitish flowers. The root is the officinal pellitory, and is used as an irritant and sialogogue. Called also {bertram}, and {pellitory of Spain}. (b) The feverfew ({Chrysanthemum Parthenium}); -- so called because it resembles the above.