Definition of angiosperm
: any of a class (Angiospermae) or division (Magnoliophyta) of vascular plants (such as magnolias, grasses, oaks, roses, and daisies) that have the ovules and seeds enclosed in an ovary, form the embryo and endosperm by double fertilization, and typically have each flower surrounded by a perianth composed of two sets of floral envelopes comprising the calyx and corolla — called also
flowering plant
