I asserted that up is down. That statement is false on its face.
I feel like I've seen at least one single word that means "on its face." Words with close etymology and meaning
- Superficial. If ficial were a word that would do the job.
- Prima facie has the right meaning in actual use: "That statement is prima facie false." But that's two words. I'm also not satisfied because it literally means "on first face." What I am looking for wouldn't be so qualified: It means that the qualified thing is that way no matter how many times or how deeply we look at it.
- Close but not quite: Obviously and its synonyms – clearly, indisputably, undeniably. These all have at least some connotation that the thing so qualified could be or is in dispute, but that the dispute is rejected. I want a word that refers to the nature of the thing and whose connotation is that no dispute can even be entertained. E.g., "A false statement is false on its face."
Best Answer
As jsw29 said in comment, you can't have a word that is synonymous with prima facie and means ‘true no matter how deeply you investigate’, because that's not what prima facie means.
If you want the first meaning in one word, there's the legalese facially.
If you want the second meaning, see Jason Bassford's answer.