The word "愤慨" is formed by combining the characters "愤" and "慨", both of which individually relate to strong emotional responses. "愤" denotes anger or resentment, typically arising from perceived injustice, while "慨" conveys indignation or deep emotion, often in reaction to unfairness. Together, they create a compound term where their similar meanings reinforce each other to express a heightened sense of righteous indignation or furious anger.