What is the Gaelic word for moon?

The Gaelic word for moon depends on which Gaelic language you mean. There are several:

* Irish: gealach (pronounced roughly as "g'l-ack")

* Scottish Gaelic: gealach (pronounced similarly to the Irish)

* Manx: yn eayn (pronounced roughly as "uhn ayne")

So, there isn't one single answer without specifying which Gaelic language.