from The Century Dictionary.
- noun A genus of fishes, constituting the family Chiasmodontidæ, noted for voracity and for the enormous distensibility of their stomach and integuments, which permits them to swallow fishes larger than themselves. C. niger, the black swallower, is the only known species.
Sorry, no etymologies found.
This fish, the chiasmodon niger, is also being called the great swallower -- it can ingest prey that's actually bigger than it and store it in its huge stomach.