foolfish

from The Century Dictionary.

• noun A kind of plaice, Pleuronectes glaber: so called from the readiness with which it takes any bait.
• noun A balistoid fish, Monacanthus hispidus; the long-finned file-fish: so called from its method of swimming with a wriggling motion with its mouth upward, by means of undulations of its dorsal fin.

from the GNU version of the Collaborative International Dictionary of English.

• noun The orange filefish. See filefish.
• noun The winter flounder. See flounder.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun filefish
• noun winter flounder