1. To support or uphold claims with evidence or arguments; to maintain the validity of assertions made
The company must sustain claims that its product is environmentally friendly.
A empresa deve sustentar as reclamações de que seu produto é ecologicamente correto.
2. In legal contexts, to uphold or validate claims presented in court
The judge sustained claims that the defendant was responsible for the damages.
O juiz sustentou as alegações de que o réu era responsável pelos danos.