sour definition

1. a cocktail made of a liquor (especially whiskey or gin) mixed with lemon or lime juice and sugar
2. the taste experience when vinegar or lemon juice is taken into the mouth
3. the property of being acidic
4. go sour or spoil
• examples: The milk has soured
• examples: The wine worked
• examples: The cream has turned--we have to throw it out
5. make sour or more sour
6. smelling of fermentation or staleness
7. having a sharp biting taste
8. one of the four basic taste sensations; like the taste of vinegar or lemons