It's definitely not eternity/forever because it's missing the second symbol. I don't think it means water either. I don't think water has a dot above it. Too bad because it looks nice.
Sorry dude, that doesn't say eternity. You're missing the second kanji. Eternity is eien. Yours says 'water'. That's what you get for picking your tattoo from the wall. Don't trust a tattoo artist on the meaning of kanji. Unless they're Japanese.
matty you signed your own sh1t. omg lmfao, wash that sh1t off your arm get a real tat, open your eyes before you point at the wall, thanks for lettin me laugh at you