1. A hidden or concealed corridor, tunnel, or route that allows passage from one place to another without being seen or detected
The old castle had a secret passage that led from the basement to the gardens.
O castelo antigo tinha uma passagem secreta que levava da cave para os jardins.
2. A clandestine or covert way to achieve something or access information
They found a secret passage to obtain the documents without raising suspicion.
Encontraram uma passagem secreta para obter os documentos sem levantar suspeitas.