say it: luh-JIT-uh-muh-see
legitimacy is a noun meaning "lawfulness by virtue of being authorized or in accordance with law". It carries 2 recorded senses.
lawfulness by virtue of being authorized or in accordance with law
undisputed credibility
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for legitimacy come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.