suicide door
/ˌs(j)uːɪsʌɪd ˈdɔː/noun
1A metaphorical exit door used by those who commit suicide.
2A dangerously positioned door, specifically one which opens to a steep drop.
3On a motor vehicle: a rear-hinged door for a passenger or driver, often perceived as dangerous due to the risk of it opening while the vehicle is in motion.
Origin
Mid 18th century. From suicide + door.