sourness

adjective

1. having the sharp, acid taste of lemon juice, vinegar, green fruit, etc.
2. made acid or rank by or as by fermentation: sour milk
3. 1. cross, bad-tempered, peevish, morose, etc.: a sour mood
   2. ill-disposed and bitter: sour toward former associates
4. below what is usual or normal; poor; bad: his game has gone sour
5. distasteful or unpleasant
6. gratingly wrong or off pitch: a sour note
7. excessively acid: said of soil
8. tainted with sulfur compounds: said of gasoline, etc.

noun

1. that which is sour; something sour
2. ☆ a cocktail made with lemon or lime juice, sugar, and, usually, soda water: a whiskey sour

transitive verb, intransitive verb