1. A reply that addresses the main points or issues in detail; a response that is meaningful, concrete, and goes beyond superficial or evasive answers
The politician avoided giving a substantive reply to the journalist's question about the scandal.
O político evitou dar uma resposta substantiva à pergunta do jornalista sobre o escândalo.
2. In legal or formal contexts, a response that deals with the merits or substance of a matter rather than procedural issues
The defendant's lawyer requested a substantive reply to the accusation before proceeding with trial.
O advogado do réu solicitou uma resposta substantiva à acusação antes de prosseguir com o julgamento.