Any of several large freshwater turtles of the family Chelydridae of North, Central, and northern South America, having a rough shell and powerful hooked jaws that close with a snap, especially the common North American species Chelydra serpentina and the alligator snapping turtle of the south-central United States.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.