The noun legitimacy means authenticity. If you found an old copy of the Gettysburg Address in your grandmother's attic, you'd have to question its legitimacy when you realized it was written on the back of a car advertisement.

Legitimacy comes from the Latin verb legitimare, which means lawful. Legitimacy, then, refers to something that is legal because it meets the specific requirements of the law. The legitimacy of various countries' presidential elections is often discussed, with monitors keeping track of the voting procedures to make sure they follow all the necessary rules.

Definitions of legitimacy
  1. noun
    lawfulness by virtue of being authorized or in accordance with law
    see moresee less
    unlawfulness by virtue of not being authorized by or in accordance with law
    type of:
    the quality of conforming to law
  2. noun
    undisputed credibility
    synonyms: authenticity, genuineness
    see moresee less
    real McCoy, real stuff, real thing
    informal usage attributing authenticity
    type of:
    believability, credibility, credibleness
    the quality of being believable or trustworthy
Word Family

Test prep from the experts

Boost your test score with programs developed by Vocabulary.com’s experts.

  • Proven methods: Learn faster, remember longer with our scientific approach.
  • Personalized plan: We customize your experience to maximize your learning.
  • Strategic studying: Focus on the words that are most crucial for success.


  • Number of words: 500+
  • Duration: 8 weeks or less
  • Time: 1 hour / week


  • Number of words: 500+
  • Duration: 10 weeks or less
  • Time: 1 hour / week


  • Number of words: 700+
  • Duration: 10 weeks
  • Time: 1 hour / week