to give someone the moon door 

To break up with somebody.

Alternatively, it means to fire somebody from a job.

Basically, the word describes any situation in which someone's position or status is completely stripped away from them in one fell swoop.

This phrase derives from the book and TV series, Game of Thrones, in which there is a castle on a high mountain with a hatch built into the floor. This hatch is called the "Moon Door." When opened, the Moon Door releases people into mid air, so that they fall directly to the floor of the Vale far below.

I finally gave Sally the moon door.

Woah, bro, sorry to hear that. Was it a tough breakup?

No. Once she was gone, it was completely over.

{to give someone the moon door]

to give someone the moon door by Ae5Ea8 March 14, 2015