I’m developing out a campaign setting right now, and I’m running into difficulty coming up with a name for the world in its entirety. Here, in the real world, we basically just ended up calling our planet “dirt” or “ground” and I honestly can’t figure out a reason a non-spacefaring people would call it anything else!

Obviously this isn’t that important and no one will question if it just has a silly fantasy name, but what do y'all think? Basically every setting does it, but does it really make sense?

I mean, depending on the setting, other planes of existence exist. Meaning that calling their planet Dirt feels a bit vague, especially with the elemental plane of earth. Think of other planes of realities and their names, Heaven is a version of the word haven, the Abyss is an eternally dark layer filled with horrors and Limbo is eternal chaos with no beginning, end and meaning.

So what would everyone think is special about their world?

I mean ... it's religious as base, right? In the beginning, Hogfather created the Heavens and the Earth. Straight out of your religious text of choice.

We do have a name for the Earth. Not dirt, but Earth. The life giving mother of all. Gaia, to some. Terra. Dunya. Sanskrit. But mostly, we just call it the Earth.

But for a campaign world, if you want to name the planet, propably let the creator god give it a name. Like, I'm sure Moradin would have named the world Anvil - or something.

World… Anvil… say that again

Just pick another earth language, and pick an English name, then run run it trough a google or equivalent translator

Dirt = charkh or khashak in Dari

Every culture has a name for their world. But every culture perceives the world differently, so their names will vary. Any society short of a modern, educated, globally-connected society will only have knowledge of their own small portion of the world. Go look at the maps drawn by pre-modern civilizations. They always put themselves in the center, it gets blurrier the farther out you go, until eventually you reach a border that's labeled either "Endless Ocean" or "Here there be monsters" or both. 

As an example, let's use a map with which we are familiar. Imagine your campaign world uses the map of our world's geography. The cultures that line the coasts of the Mediterranean Sea might call their world "Mare Centralis" (or Central Sea in Latin), indicating that they perceive this sea to be the center of their known world. But a culture to the south, inhabiting the desert of North Africa might call the world "Al sahra' Alhaya" (or The Living Desert in what google translate tells me is Arabic). 

And then, of course, each culture will have their own name for the lands that some other culture calls home, which just complicates things further. So unless your campaign exists in some futuristic globally-unified setting, there will never be just one name for the world. After all, we live on Earth, and Terra, and Gaia, and Chikyu, and Aarde, Jord, Domhan, Yer, Papatūānuku, Delkhii, Zamin, and a hundred other words that all mean the same place, but to different people. 

It's all a matter of perspective.