hatchetfish
Concise Oxford English Dictionary © 2008 Oxford University Press:
hatchetfish
▶noun (pl. same or hatchetfishes) a deep-bodied laterally compressed tropical freshwater fish of the New World, able to fly short distances in the air by beating its broad pectoral fins. [Family Gasteropelecidae : several species.]
'hatchetfish' also found in these Oxford entries:

