fatso

[ fat-soh ]
/ ˈfæt soʊ /

noun, plural fat·sos, fat·soes. Informal: Disparaging and Offensive.

a fat person (used as a term of address).

Origin of fatso

1940–45; perhaps Fats a nickname for a fat person (see fat, -s4) + -o; also compared with fat sow, German Fettsau
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for fatso

fatso

/ (ˈfætsəʊ) /

noun plural -sos or -soes

slang a fat person: used as an insulting or disparaging term of address
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