A little translation help..

[Nerwen]

Guys, you are indeed mixing Quenya with Sindarin. They have similar words for "child", but not the same. In Quenya it's "hína/híni", in Sindarin "hên/hîn" ("chên/chîn" after a vowel).

Igorus, I believe you were almost right the first time– in Quenya it should be "Héruhin", with an accent on the "e" (assuming you mean THE Lord, not A lord). Though "Eruhin" would have the same significance.

Meanwhile the Sindarin version could be "Hên i Chîr", "Hên i Cheron" or "Hên i Vrannon", but I'm not sure which of those, if any, would be the proper way to refer to THE Lord.

I think that's about as good an answer as you're going to get, but be aware that Tolkien's languages are incomplete, and that he kept revising them throughout his life– something to keep in mind before you rush to the tattoo parlour.

Edit:X'd with Pitch; fixed typo.