noun
: any of various dogfishes constituting the family Squalidae and distinguished by the presence of a spine in or immediately anterior to each dorsal fin: as
a. : a common very destructive dogfish ( Squalus acanthias ) of both coasts of the No. Atlantic that becomes about four feet long and has the fin spines stout and prominent
b. : a similar dogfish ( Squalus suckleyi ) of the Pacific coast of No. America