Any of several large, long-eared, long-legged hares of the genus Lepus.
To move or begin to move rapidly or suddenly: "A rear tire blew out and the car jackrabbited out of control” ( Sonny Kleinfield).
Moving or beginning to move in a sudden, rapid manner: won the race with a jackrabbit start.
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.