any herbaceous plant of the genus Trillium, of Asia and North America, having a whorl of three leaves at the top of the stem with a single central white, pink, or purple three-petalled flower: family Trilliaceae
Word origin
C18: from New Latin, modification by Linnaeus of Swedish trilling triplet
trillium in American English
(ˈtrɪliəm)
noun
any of a genus (Trillium) of perennial plants of the lily family, having an erect stem that bears a whorl of three leaves and a single flower with three green sepals and three petals that change color as they mature