A stairway (often on the outside of a building) that permits exit in the case of fire or other emergency WordNet 3.0 & Open English WordNet

An emergency exit in a structure is a special exit for emergencies such as a fire or other emergencies; the combined use of regular and special exits allows for faster evacuation, while it also provides an alternative if the route to the regular exit is blocked. Wikipedia

A fire escape is a special kind of emergency exit, usually mounted to the outside of a building or occasionally inside but separate from the main areas of the building. Wikipedia

Special exit for use during emergencies Wikidata

A door, ladder, stairs or passage used to evacuate a building in case of fire. OmegaWiki

An exit used only when a place must be evacuated quickly, such as in case of fire. OmegaWiki

An exit that is designed to allow rapid evacuation in the case of emergencies such as a fire. Wiktionary

Exit for evacuation. Wiktionary (translation)

Any of the series of emergency doors, ladders, or stairs used to evacuate a building if a fire breaks out. Wiktionary