Definify.com
Webster 1913 Edition
Blackfish
Black′fish
,Noun.
 1. 
(Zool.) 
A small kind of whale, of the genus 
Globicephalus
, of several species. The most common is Globicephalus melas
. Also sometimes applied to other whales of larger size. 2. 
(Zool.) 
The tautog of New England (
Tautoga
). 3. 
(Zool.) 
The black sea bass (
Centropristis atrarius
) of the Atlantic coast. It is excellent food fish; – locally called also black Harry
. 4. 
(Zool.) 
A fish of southern Europe (
Centrolophus pompilus
) of the Mackerel family. 5. 
(Zool.) 
The female salmon in the spawning season. 
☞ The name is locally applied to other fishes. 
Definition 2025
blackfish
blackfish
English
Noun
blackfish (plural blackfishes or blackfish)
- (chiefly Scotland) The Atlantic salmon, Salmo salar, especially a female after spawning. [from 16th c.]
 - Any of various dark-coloured fish of the Old World, especially the rudderfish (Centrolophus niger). [from 17th c.]
 - A pilot whale, genus Globicephalus (occasionally also used for various other whales). [from 17th c.]
 - (Canada, US) Either of two dark-coloured fish of the west Atlantic, the tautog of New England (Tautoga onitis) and the black sea bass (Centropristis striata). [from 18th c.]
 -  (Australia, New Zealand) Any of various dark-coloured fishes of Australasia, especially the luderick, Girella tricuspidata, and a freshwater fish, Gadopsis marmoratus. [from 18th c.]
-  1985, Peter Carey, Illywhacker, Faber and Faber 2003, p. 337:
- The creek was reputed to contain blackfish and Nathan […] arranged the extraordinary collection of American lures he had inherited from an uncle.
 
 
 -  1985, Peter Carey, Illywhacker, Faber and Faber 2003, p. 337: