Definition that contains atop
- tier one of two or more layers one atop another
- triceratops huge ceratopsian dinosaur having three horns and the neck heavily armored with a very solid frill
- frill (paleontology) a bony plate that curves upward behind the skull of many ceratopsian dinosaurs
- velociraptor small active carnivore that probably fed on protoceratops; possibly related more closely to birds than to other dinosaurs
- keratoconus abnormal cone-shaped protrusion of the cornea of the eye; can be treated by epikeratophakia
- sego lily perennial plant having clusters of one to four showy white bell-shaped flowers atop erect unbranched stems; edible bulbs useful in times of scarcity; eastern Montana and western North Dakota south to northern Arizona and northwestern New Mexico
- order ranunculales herbs, shrubs and trees: includes families Ranunculaceae; Annonaceae; Berberidaceae; Magnoliaceae; Menispermaceae; Myristicaceae; Nymphaeaceae; Lardizabalaceae; Lauraceae; Calycanthaceae; Ceratophyllaceae; Cercidiphyllaceae
- catoptric of or relating to catoptrics; produced by or based on mirrors
- parkeriaceae coextensive with the genus Ceratopteris; sometimes included in family Polypodiaceae
- genus peripatopsis type genus of Peripatopsidae; onychophorans of chiefly Asiatic and African tropical regions