What is another word for Backside entrance?

Here are some other words for "backside entrance," depending on the context and desired tone:

Formal:

* Rear entrance

* Service entrance

* Back door (this is fairly common and neutral)

* Secondary entrance

* Poste riore entrance

Informal:

* Back way

* Side door (if it's on the side of the building)

* Fire escape (if it's a fire escape)

Figurative/Slang:

* Back alley

* Secret passage

The best choice depends on your specific context and audience.