having a sharp acid taste, like the taste of a lemon or a fruit that is not ready to be eaten [≠ sweet; ↪ bitter]: ➔ sweet-and-sour
Rachel sampled the wine. It was sour.
milk or other food that is sour is not fresh and has a bad taste
turn/go sour (=become sour)
unfriendly or looking bad-tempered
sour look/face/smile etc
Eliza was tall and thin, with a rather sour face.
a sour-faced old man
if a relationship or plan turns or goes sour, it becomes less enjoyable, pleasant, or satisfactory:
As time went by, their marriage turned sour.
The meeting ended on a sour note with neither side able to reach agreement.
used to say that someone is pretending that they dislike something because they want it but cannot have it - used to show disapproval
—sourness noun [uncountable]WORD FOCUS: taste
delicious/tasty tastes very good
disgusting tastes very bad
hot/spicy has a lot of spices
bland boring and with not very much taste
sweet has a lot of sugar
salty has a lot of salt
sour used about fruit that is not sweet
bitter used about coffee, chocolate, or medicine that is not at all sweettaste
➔ See also taste