| n. | 1. | The state of being illegitimate. |
| Noun | 1. | illegitimacy - the status of being born to parents who were not married Synonyms: bar sinister, bastardy |
| 2. | illegitimacy - unlawfulness by virtue of not being authorized by or in accordance with law Antonyms: legitimacy - lawfulness by virtue of being authorized or in accordance with law |