The noun sour has 3 senses (no senses from tagged texts)
1. sour -- (a cocktail made of a liquor (especially whiskey or gin) mixed with lemon or lime juice and sugar)
2. sour, sourness, tartness -- (the taste experience when vinegar or lemon juice is taken into the mouth)
3. sourness, sour, acidity -- (the property of being acidic)
Overview of verb sour
The verb sour has 2 senses (first 2 from tagged texts)
1. (2) sour, turn, ferment, work -- (go sour or spoil; "The milk has soured"; "The wine worked"; "The cream has turned--we have to throw it out")
2. (1) sour, acidify, acidulate, acetify -- (make sour or more sour)
Overview of adj sour
The adj sour has 6 senses (first 1 from tagged texts)
1. (1) sour, rancid -- (smelling of fermentation or staleness)
2. sour -- (having a sharp biting taste)
3. sour -- (one of the four basic taste sensations; like the taste of vinegar or lemons)
4. off, sour, turned -- (in an unpalatable state; "sour milk")
5. false, off-key, sour -- (inaccurate in pitch; "a false (or sour) note"; "her singing was off key")
6. dark, dour, glowering, glum, moody, morose, saturnine, sour, sullen -- (showing a brooding ill humor; "a dark scowl"; "the proverbially dour New England Puritan"; "a glum, hopeless shrug"; "he sat in moody silence"; "a morose and unsociable manner"; "a saturnine, almost misanthropic young genius"- Bruce Bliven; "a sour temper"; "a sullen crowd")