Green’s Dictionary of Slang

puss n.2

[Irish pus, the mouth, a sulky expression]

1. [late 19C+] the mouth.

2. [late 19C+] a face.

3. [1910s+] (Irish) a sulky look; also as v., to pout or sulk; thus have a puss on

In derivatives

pussful (n.)

[1970s] (US) a sufficiency, esp. of drink.

In phrases

have a puss on (v.)

[1950s+] to display a sulky or ill-humoured face.

shut one’s puss (v.)

[1950s] (US) to be quiet, to stop talking; also as imper.