黑牢

hēiláo

黑牢 — hēiláo

1. an illicit or secret prison; a dark dungeon used to detain or torture prisoners

   他被关进了黑牢，音讯全无。 tā bèi guānjìn le hēi láo yīnxùnquánwú — He was locked up in a secret prison, and there was no news of him.