tur·tle
noun/ˈtɜːtl/
/ˈtɜːrtl/
Idioms 
enlarge image(North American English also sea turtle)a large reptile with a hard round shell that lives in the sea海龟 - (North American English, informal) any reptile with a large shell, for example a tortoise or terrapin
（任何种类的）龟；陆龟；水龟；鳖
Word Originmid 16th cent.: apparently an alteration of French tortue, from medieval Latin tortuca, of uncertain origin.
Idioms
turn turtle
- (of a boat) to turn over completely while sailing
（在航行中）倾覆，翻