mackerel shark definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
any of a family (Lamnidae) of large, partly warm-blooded sharks, including the porbeagle, mako, and white sharks
mackerel shark definition by American Heritage Dictionary
Any of various sharks of the family Lamnidae, including the great white shark, mako, and porbeagle, having a pointed snout, a nearly symmetrical tail, and a reputation for aggressiveness.