pə̇|rärə|kü noun
( -s )
Etymology: Portuguese pirarucu, pirarucú, from Tupi pirá-rucú, pirá-urucú, literally, red fish
: a large-scaled osteoglossid fish ( Arapaima gigas ) of the rivers of northern So. America that is held to attain a length of 15 feet and a weight of 500 pounds and is of great importance in the diet of the natives of the area