Definition of "bitterness"

bitterness

/ˈbɪtənəs/

noun
countable and uncountable, plural bitternesses
1. The quality of having a bitter taste.
2. The quality of feeling bitter; acrimony, resentment; the quality of exhibiting such feelings.
  Quotations
  She suspected that during the summer her father had mentioned Brian’s windfall to Billy and that father and son had then traded snidenesses and bitternesses about the W—— Corporation and bourgeois Robin and leisure-class Brian.
  2001, Jonathan Franzen, The Corrections
3. The quality of eliciting a bitter, humiliating or harsh feeling.
4. Harsh cold.