sourpuss

the word 'sourpuss' is a 20th-century american english colloquialism formed by combining two pre-existing english words. the first element, 'sour', extends its meaning from a literal acidic taste to the metaphorical sense of a disagreeable or morose disposition, a semantic shift common in many languages. the second element, 'puss', entered english slang via irish immigrants, originally referring to the mouth and face. the compound thus paints a vivid, literal picture of a person whose facial expression is permanently fixed in a sour, displeased scowl. this humorous, slightly mocking term exemplifies how english creates new descriptive nouns by blending familiar concrete images to capture an abstract personality trait.

Structure: sour + puss sour: from old english sūr, meaning 'having an acid taste like lemon or vinegar'. in this compound, it functions as an adjective meaning 'bad-tempered, disagreeable'. puss: a colloquial or dialectal english word (of celtic origin, from irish pus meaning 'mouth, lips'), used as a term for the face, especially one with a sour expression.