IPA: //ʌnˈbɪtə//
KK: /ʌnˈbɪtər/
Describing someone who does not feel anger or resentment towards others.
Despite the unfair treatment, she remained unbitter and forgiving.
Unbitter → It is formed from "un-" (meaning not) and "bitter" (from Old English "bitter", meaning having a sharp taste or smell). The word "unbitter" means not having a sharp taste or smell, or being free from bitterness.
Think of 'not' ('un-') combined with 'sharp taste' ('bitter') to remember that 'unbitter' means something that is not sharp or bitter in taste.