deinonychus /daɪˈnɒnɪkəs/ noun1 •A medium agile dinosaur, of the genus Deinonychus, of the Cretaceous period, characterized by having a large, curved claw on each hind foot.Bella kept half an eye out for the deinonychi. The deinonychus dinosaurs with the teeth and raking claws were big solid humans in the real. — 1994 formsdeinonychi · deinonychuses