ˈsilfēəm noun
Etymology: Latin, from Greek silphion; of North African origin
1. plural sil·phia -ēə : an extinct umbelliferous plant of the genus Ferula not definitely identifiable as to species but well known to the ancient Greeks and used by them medicinally
2. capitalized
[New Latin, from Latin]
: a large genus of tall No. American perennial herbs (family Compositae) having coarse heads of yellow flowers with fertile rays and broad flat winged achenes — see cup plant