Is Dimension X considered public domain?

[Original TMNT Cartoon Fan]

With no Internet as we know it today being around, the name Dimension X remained mysterious for many young TMNT fans back in the late 1980's and early 1990's. If you didn't know it back then, nowadays you can easily learn its name originates from an American science fiction radio drama series airing from April 1950 to September 1951 over NBC Radio.

Googling around in late January 2024, the name appears and has appeared in a lot of popular culture like books, comics and video games through the years. It seems that DC Comics, Marvel Comics and the stageplay adptation of Stranger Things all utilize their own Dimension X.

So is Dimension X as a location (probably an alternate universe) considered public domain?

[frank_one]

Maybe the name "Dimension X" is so generic that cannot be copyrighted.

[Allio]

Yeah, it’s just so generic. You could probably find it in a lot of sci-fi stories.

[neatoman]

Maybe the name "Dimension X" is so generic that cannot be copyrighted.

Trademarked. And yes, it probably is. As for copyright, the Dimension X in TMNT, Marvel, Stranger Things clearly aren't the same setting or based on the same setting. It's kinda like... Alright you know how Asgard is a setting in mythology and even though the Asgard in Marvel and God of War aren't the same, they still clearly share a common origin? Unless these Dimension X setting are share important details, they aren't based on the same thing.

[IMJ]

It probably can be trademarked and copyrighted successfully under it's specific use case somehow, but it would likely be found in court to be too broad a concept to bar others from using it in entertainment under a different paradigm than "Mutant Turtles" and "pink talking brains". Etc...

Truth is that one lawyer might advise to add it under some kind protective language while another would say "well you can do it, but it would have to be a very arbitrary use by someone else for you to be able to enforce it".

[Original TMNT Cartoon Fan]

Today I learnt that the Transformers franchise has its own Technodrome, first appearing in a comic published on 5 December 2012. So I guess that name is also considered public domain.

https://tfwiki.net/wiki/Technodrome