mackerel shark
mack·er·el shark
noun \ˈmak-(ə-)rəl-\Definition of MACKEREL SHARK
: any of a family (Lamnidae) of large aggressive pelagic sharks that include the great white shark
Learn More About
Seen & Heard 
What made you want to look up mackerel shark? Please tell us where you read or heard it (including the quote, if possible).
