There are a fair few names that have unknown meanings, and remain “meaningless”.
[name]Tatiana[/name] is one of those names.
Perhaps we should make a list of the names that lack official meanings, and see what we can put together. Perhaps we can scrap together our knowledge and find an unofficial official meaning for some. 
The list so far:
[name]Tatiana[/name]
Please add!
I can tell you right know, [name]Tatiana[/name] is Slavic, and it means “fairy queen”. 
Anyone else? I have my trusty name book that I bought at a thrift shop when I was like, 10 or 11. lol
[name]Isannah[/name], I love it but can’t find a meaning anywhere for it!
That’s wrong I’m afraid. [name]Tatiana[/name] is Latin and means belonging to Tatius. But what Tatius means is unclear. Might it be from the Latin word tata (daddy)?
My unknown of the day: [name]ARTHUR[/name]
[name]Eleanor[/name] has meaning unknown, they do have listed the meaning of [name]Helen[/name], but [name]Eleanor[/name] doesn’t have a meaning on this namesite or any other that I’ve visited that was reputable.