SUNFISH
sunfish, centrarchid
(noun) small carnivorous freshwater percoid fishes of North America usually having a laterally compressed body and metallic luster: crappies; black bass; bluegills; pumpkinseed
sunfish
(noun) the lean flesh of any of numerous American perch-like fishes of the family Centrarchidae
Source: WordNet® 3.1
Etymology
Noun
sunfish (plural sunfish or sunfishes)
Any of various small freshwater fishes of the family Centrarchidae, often with iridescent colours and having a laterally compressed body.
Any of various large marine fishes of the family Molidae that have an oval compressed body.
Source: Wiktionary
Sun"fish`, n. (Zoöl.)
(a) A very large oceanic plectognath fish (Mola mola, Mola rotunda,
or Orthagoriscus mola) having a broad body and a truncated tail.
(b) Any one of numerous species of perch-like North American fresh-
water fishes of the family Centrachidæ. They have a broad, compressed
body, and strong dorsal spines. Among the common species of the
Eastern United States are Lepomis gibbosus (called also bream,
pondfish, pumpkin seed, and sunny), the blue sunfish, or dollardee
(L. pallidus), and the long-eared sunfish (L. auritus). Several of
the species are called also pondfish.
(c) The moonfish, or bluntnosed shiner.
(d) The opah.
(e) The basking, or liver, shark.
(f) Any large jellyfish.
Source: Webster’s Unabridged Dictionary 1913 Edition