'Mindoki' would be 'my know', and 'mindok' is know. There is no word-for-word translation. 

Context helps a lot, so without it, we can't really get a better idea  

Tattoos are pretty important to get right, so we'd love to help you with the runes or grammar! But we can only help so much without knowing the full phrase or sentence that's being translated. If you post the whole thing, we can figure out an alternate way to say it using only canon Dragon language words!