憤慨
ふんがい · fungai · JLPT N1 · noun
indignation
憤 = anger + 慨 = lament; both carry the heart radical 心, so indignation is anger felt in the heart
憤 is anger that wells up, and 慨 is a heavy sigh of lament. Together they name the resentment you feel when something unjust happens and you cannot let it go.