Delegitimize is a word commonly used when a person or entity seeks to undermine the validity, credibility or authority of someone or something. In simpler terms, it means making something or someone seem less legitimate, worthy, or deserving of respect or recognition. Some synonyms for delegitimize include disqualify, discredit, invalidate, nullify, weaken, undercut, diminish, and challenge. All these words reflect the idea of casting doubt on the legitimacy of a person, idea, or institution. Using such words in communication can be highly effective in conveying the intended message and highlighting the shortcomings of the subject in question.