airtight; hermetically sealed; impenetrable (e.g., defense, encirclement, secret)
这间地下室的门窗都关得密不通风，确保了储藏物品的安全。
The doors and windows of this basement were sealed airtight, ensuring the safety of the stored items.
Next Idiom
airtight; hermetically sealed; impenetrable (e.g., defense, encirclement, secret)