1. To strengthen or increase the effectiveness of defensive measures, capabilities, or systems
The country decided to beef up defense spending after the security threat.
O país decidiu reforçar a defesa após a ameaça à segurança.
2. To make defensive arguments or positions stronger and more convincing
The lawyer will beef up the defense with additional evidence.
O advogado vai reforçar a defesa com evidências adicionais.