[Middle English indignacioun, from Old French indignation, from Latin indignātiō, indignātiōn-, from indignātus past participle of indignārī, to regard as unworthy, from indignus, unworthy; see indign.]
noun
Anger aroused by something unjust, mean, or unworthy. See synonyms at anger
The American Heritage® Dictionary of the English Language, Fourth Edition