Fàilte - meaning "Welcome" in Irish Gaelic, with a variation of "céad míle fáilte" meaning "a hundred thousand welcomes".
Sláinte meaning "health" and Sláinte Mhaith meaning "good health". For Scottish Gaelic you would reverse the accent mark, as in slàinte or slàinte mhath.
You can find the Sláinte sign here.
Above, example of an anniversary gift, Sláinte, with established date. Distressed black letters, faded sage green drop shadow and shamrocks.
(note: you can request a custom order based on any of these examples)