Definition of "Sour" :
noun: the property of being acidic
noun: the taste experience when vinegar or lemon juice is taken into the mouth
noun: a cocktail made of a liquor (especially whiskey or gin) mixed with lemon or lime juice and sugar
verb: go sour or spoil
"The milk has soured."
verb: make sour or more sour
adjective: smelling of fermentation or staleness
adjective: showing a brooding ill humor
"A sour temper."
adjective: inaccurate in pitch
"A false (or sour) note."
adjective: having a sharp biting taste
adjective: in an unpalatable state
adjective: one of the four basic taste sensations; like the taste of vinegar or lemons