swellfish

[ swel-fish ]
/ ˈswɛlˌfɪʃ /

noun, plural (especially collectively) swell·fish, (especially referring to two or more kinds or species) swell·fish·es.

Origin of swellfish

An Americanism dating back to 1800–10; swell + fish
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for swellfish

swellfish

/ (ˈswɛlˌfɪʃ) /

noun plural -fish or -fishes

a popular name for puffer (def. 2)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012