Douglas Harper's Etymology Dictionary
pug-nose
1778, from pug (n.) based on fancied similarity to the nose of either the monkey or the dog. Related: Pug-nosed.
WordNet
pug-nose
adj. having a blunt nose; "a pug-nosed boy with freckles"; "a snub-nosed automatic" [syn: pug-nosed, snub-nosed]