Green’s Dictionary of Slang

pus-gut n.

also pus-guts, pussy-guts
[pussy adj.1 /pron. SE purse, i.e. a full purse + gut n. (1a)]

[mid-19C+] a term of abuse for someone with a fat stomach; the fat stomach itself.

In derivatives

pus-gutted (adj.) (also pus-gut, pusley-gutted, pussle-gutted, pussy-gutted)

corpulent.