'mackerel shad' definitions:

Definition of 'mackerel shad'

(from WordNet)
noun
Small silvery fish; Nova Scotia to Brazil [syn: mackerel scad, mackerel shad, Decapterus macarellus]

Definition of 'mackerel shad'

From: GCIDE
  • mackerel scad \mackerel scad\, mackerel shad \mackerel shad\n. (Zool.) A small silvery fish (Decapterus macarellus) found from Nova Scotia to Brazil. [WordNet 1.5]