noun
evacuation exit; escape hatch
A door or opening specifically designed for evacuation in emergencies, such as in buildings, ships, or aircraft.
火災の際は、避難口から外に出てください。
In case of fire, please exit through the evacuation door.
この建物には複数の避難口が設置されている。
This building is equipped with multiple evacuation exits.
Compound of 避難 (ひなん, 'evacuation') and 口 (ぐち, 'opening' or 'exit').