from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Slang A habitually gloomy or sullen person.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A person who is habitually gloomy, sullen or miserable; a grouch.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. someone with a habitually sullen or gloomy expression
sour + puss2.(American Heritage® Dictionary of the English Language, Fourth Edition)
sour (“bad-tempered”) + puss (“slang for “mouth””) (Wiktionary)