1. Go sour or spoil
   "The milk has soured"
   - turn, ferment, work 
2. Make sour or more sour
   - acidify, acidulate, acetify

1. Smelling of fermentation or staleness
   - rancid 
2. Having a sharp biting taste 
3. One of the four basic taste sensations; like the taste of vinegar or lemons 
4. In an unpalatable state
   "sour milk"
   - off, turned 
5. Inaccurate in pitch
   "a sour note"
   - false, off-key 
6. Showing a brooding ill humour
   "a sour temper"
   - dark, dour, glowering, glum, moody, morose, saturnine, sullen

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
   - sourness, tartness 
3. The property of being acidic
   - sourness, acidity

Derived forms: souring, sours, soured, sourest, sourer

See also: acerb, acerbic, acetose, acetous, acid, acidic, acidulent, acidulous, astringent, dry, ill-natured, ill-smelling, inharmonious, lemonlike, lemony, malodorous, malodourous, minging [Brit], pongy [Brit], soured, souring, sourish, sourly, sourness, stinky, subacid, tangy, tart, tasty, unharmonious, unpleasant-smelling, vinegarish, vinegary, whiffy [Brit]

Type of: change state, change taste, cocktail, gustatory perception, gustatory sensation, taste, taste perception, taste property, taste sensation, turn

Antonym: sweet, sweeten

Encyclopedia: Sour

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