1. to make someone feel angry, resentful, or hostile
2. to make something unpleasant or difficult to bear

Examples

• The unfair treatment embittered him against his former employer.
• Years of disappointment had embittered the old man.
• The harsh criticism embittered her toward the entire industry.
• Don’t let one bad experience embitter you against all teachers.
• The scandal embittered relations between the two countries.
• His constant complaints embittered the atmosphere at work.