‖n. [ NL., fr. Gr. &unr_; (see Tri-) + &unr_; a claw. ] (Zool.) A genus of fresh-water or river turtles which have the shell imperfectly developed and covered with a soft leathery skin. They are noted for their agility and rapacity. Called also
☞ The common American species (Trionyx ferox syn. Aspidonectus ferox) becomes over a foot in length and is very voracious. Similar species are found in Asia and Africa. [ 1913 Webster ]