I know the vocabulary for saying "Beautiful young lady", but am not sure of the word order.
Is it bantiarna álainn óg or bantiarna óg álainn?? Or is there a better way of saying it??

bantiarna, as far as I'm aware, is more like 'lady' as an official title, and, honestly, I can't seem to recall ever coming across it naturally before. My suggestion would be to use bean instead. So bean óg álainn would be my inclination, though I'm not certain about the order of adjectives in Irish.

You could also say "Cailín álainn" (which would eliminate the need for "óg," and I think would be more natural)

Wait for more.

Redwolf

Both orders occur ("bean óg álainn"/"bean álainn óg"), but "bean óg álainn" is more common.

For "young lady" there is "ógbhean", too, so "ógbhean álainn" could be used as well.

There are also some poetic (less used) terms for a young woman, such as ainnir, which would allow an alliterative expression such as this:

ainnir álainn
beautiful lady

Incidentally, there's a theory that the word ainnir came into Gaelic from Basque, perhaps before the Gaels invaded Ireland from Northern Spain.

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I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.

Thanks all

If you are curious, yes, there is a slight difference. In Irish (the opposite of English, for example), the most essential adjective (often a genitive) is the last one that appears. So for example bord beag adhmaid or bean gharbh an tí. Thus, bean óg álainn is a beautiful woman who is young and bean álainn óg is a young woman who is beautiful.
At least that is my understanding of it!

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