adj.
1.smelling of fermentation or staleness
2.having a sharp biting taste
3.one of the four basic taste sensations
4.in an unpalatable state
5.inaccurate in pitch
6.showing a brooding ill humor sour n.
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 sour v.
1.go sour or spoil
2.make sour or more sour