1. to make something acceptable or valid according to law, rules, or social standards
2. to show or prove that something is reasonable or necessary

Examples

• The new evidence helped legitimize his claim to the inheritance.
• The company tried to legitimize its controversial business practices.
• Her academic credentials legitimize her position as an expert.
• The treaty legitimized the new government’s authority.
• He worked hard to legitimize his unconventional teaching methods.
• The court ruling legitimized same-sex marriage in the state.
• The research findings legitimize the need for policy changes.