To discredit is defined as to cast doubt on the truth of something or someone, or to damage a person's reputation.
(verb)When you tell everyone that your professor knows nothing and show evidence to prove it, this is an example of a time where you discredit your professor.
See discredit in Webster's New World College Dictionary
transitive verb
noun
See discredit in American Heritage Dictionary 4
transitive verb dis·cred·it·ed, dis·cred·it·ing, dis·cred·its
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