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.smelling of fermentation or staleness
5.having a sharp biting taste
6.one of the four basic taste sensations; like the taste of vinegar or lemons
7.in an unpalatable state;
sour milk
8.inaccurate in pitch;
a false (or sour) note
9.showing a brooding ill humor;
a dark scowl
1.go sour or spoil;
The milk has soured
2.make sour or more sour