different between sourness vs bitterness

English

From Middle English sowrenesse, sournesse, from Old English s?rnes (“sourness”), equivalent to sour +? -ness.

sourness (countable and uncountable, plural sournesses)

From Middle English bitternesse, biternesse, from Old English biternes (“bitterness; grief”), equivalent to bitter +? -ness.

bitterness (countable and uncountable, plural bitternesses)

The quality of having a bitter taste.
The quality of feeling bitter; acrimony, resentment; the quality of exhibiting such feelings.
She kept her bitterness about her mistreatment for the rest of her life.
the bitterness of his words
The quality of eliciting a bitter feeling; humiliating, harsh.
Nothing could assuage the bitterness of their defeat.
Harsh cold.
The bitterness of the winter caught us all by surprise.

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