Is sour a synonym of sweet?

No, sour is not a synonym of sweet. They are antonyms, meaning they have opposite meanings.

* Sweet refers to a pleasant taste, often associated with sugar.

* Sour refers to a sharp, unpleasant taste, often associated with acids.

For example:

* Lemonade can be sweet or sour depending on how much sugar is added.

* A lemon is sour, while a strawberry is sweet.