The Collaborative International Dictionary of English v.0.48:
Turtle \Tur"tle\, n. [Probably the same word as the word
preceding, and substituted (probably by sailors) for the
Spanish or Portuguese name; cf. Sp. tortuga tortoise, turtle,
Pg. tartaruga, also F. tortue, and E. tortoise.]
1. (Zool.) Any one of the numerous species of Testudinata,
especially a sea turtle, or chelonian.
Note: In the United States the land and fresh-water tortoises
are also called turtles.
2. (Printing) The curved plate in which the form is held in a
type-revolving cylinder press.
Alligator turtle, Box turtle, etc. See under Alligator,
green turtle (Zool.), a marine turtle of the genus
Chelonia, having usually a smooth greenish or
olive-colored shell. It is highly valued for the delicacy
of its flesh, which is used especially for turtle soup.
Two distinct species or varieties are known; one of which
(Chelonia Midas) inhabits the warm part of the Atlantic
Ocean, and sometimes weighs eight hundred pounds or more;
the other (Chelonia virgata) inhabits the Pacific Ocean.
Both species are similar in habits and feed principally on
seaweed and other marine plants, especially the turtle
Turtle cowrie (Zool.), a large, handsome cowrie (Cypraea
testudinaria); the turtle-shell; so called because of its
fancied resemblance to a tortoise in color and form.
Turtle grass (Bot.), a marine plant (Thalassia
testudinum) with grasslike leaves, common about the West
Turtle shell, tortoise shell. See under Tortoise.