Sour
Definition 1 of 4
Pro Tip 1/3
Often Negative
Sour in taste often implies something is too acidic or maybe spoiled, suggesting a bad experience. The soup has a sour flavor; I can't eat it.
Pro Tip 2/3
Metaphorical Use
Sometimes 'sour' is used metaphorically to describe an experience that left a bad impression. Losing the game left a sour taste in his mouth.
Pro Tip 3/3
Intensity
Sour flavors range from slightly tart to intensely acidic; context helps clarify. Limes are sour, but they're great in small amounts.