1. in a way that is permitted or required by law
2. from the perspective of the law; in legal terms

Examples

• You must be legally authorized to work in this country.
• The contract is legally binding once both parties sign it.
• She legally changed her name after getting married.
• The company is legally responsible for any damages.
• Legally speaking, you have the right to remain silent.
• The building was legally demolished with proper permits.
• They are legally required to provide safety equipment.