1. (

• souring

) the process of becoming sour ;

1. (

• sour ,
• turn ,
• ferment ,
• work ,

) go sour or spoil; "The milk has soured"; "The wine worked"; "The cream has turned;

2. (

• sour ,
• acidify ,
• acidulate ,
• acetify

) make sour or more sour ;

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" ;