noun, plural (especially collectively) mack·er·el, (especially referring to two or more kinds or species) mack·er·els.
Origin of mackerel
Examples from the Web for mackerel
The mackerel is a summer fish, coming and going with the regularity of the equinoxes themselves.American Merchant Ships and Sailors|Willis J. Abbot
The mackerel came in "schools" in late summer, and sometimes were very plentiful.
Whereupon the herring, the mackerel, and the dogfish swam forward, and each claimed to be king.The Divine Adventure etc. (Works vol. 4)|Fiona Macleod
Mackerel rarely show in rough weather, even if you could put out a seine-boat and go after them.The Seiners|James B. (James Brendan) Connolly
No more lines of retreat will be kept open, and henceforth the Mackerel Brigade is to make nothing but great captures.The Orpheus C. Kerr Papers. Series 2|Robert H. Newell