dogfennel noun3 •Anthemis cotula, an annual plant native to Europe and North Africa. •(US, Canada) Any of various similar American plants, especially Eupatorium capillifolium, a perennial plant.“I aint been teasing him.” Luster said. “He was playing with that bottle full of dogfennel and all of a sudden he started up bellering.” — 1929 •A plant in the genus Chamaemelum. formsdogfennels