hammerspace

From hammer +‎ space, referring to the large mallets often produced from nowhere by cartoon characters.

hammerspace (uncountable)

1. (humorous, fiction) A storage space able to contain objects larger than itself.
   • 1996, Vincent Tagle, “Love and a single Ukclone...”, in rec.arts.anime.misc (Usenet):

     Okay, now just picture what you want to pull out of hammerspace and just reach in and grab it.

   • 2000, Jason Howe, “Hammerspace Cleaning”, in alt.fan.sailor-moon (Usenet):

     ...it's a commonly known fact that dust is physically incapable of collecting in Hammerspace, so everything is always looking brand new! I for one would want to keep my collection of--I think it's sixty-four--manga spotless!

   • 2008, Meljean Brook, Demon Night:

     I just learned how to take my sword out of my hammerspace, and I'm not afraid to use it.

• out of thin air