(adjective) according to law, rules or principles; genuine, authentic
"He had a legitimate claim against the company."
Synonyms
valid: "The defense attorney raised a valid objection to the prosecutor's attempt to introduce hearsay evidence."
lawful: "Citizens in this jurisdiction have a lawful right to own registered guns for the purpose of hunting."
appropriate: "The police officer's use of force was appropriate in light of the fact that the suspect was threatening him with a baseball bat."
Antonyms
illegitimate: "The military operation was questioned as an illegitimate use of force."
unlawful: "Solicitation of prostitution is an unlawful activity."
Common phrases: legitimate right - legitimate claim - legitimate interest - legitimate use
Note: The term "legitimate" is also used to describe children of parents lawfully married to each other.
Source: Translegal