The Collaborative International Dictionary of English v.0.48:
oilfish \oilfish\ n. A very large deep-water snake mackerel (Ruvettus pretiosus). [WordNet 1.5] oil heaterWordNet (r) 3.0 (2006):
oilfish n 1: very large deep-water snake mackerel [syn: oilfish, Ruvettus pretiosus]