a flexible rodlike structure that forms the supporting axis of the body in the lowest chordates and lowest vertebrates and in embryos of higher vertebrates
any of various minerals consisting of hydrous silicates of aluminum or potassium etc. that crystallize in forms that allow perfect cleavage into very thin leaves; used as dielectrics because of their resistance to electricity
any of various deciduous trees of the genus Tilia with heart-shaped leaves and drooping cymose clusters of yellowish often fragrant flowers; several yield valuable timber