Let’s start with an English loanword that originated in Irish: galore. In context: “Once I discovered the library’s DVD collection, I had movies galore.” Or, “When he took a photograph of the customs area, it was security guards galore.”
“Galore” is derived from the Irish, “go Leor,” meaning “enough.” As you can see, the English version is just a minor change of spelling.
“Ceart go Leor” means “Everything is alright” in Irish — at least in Cork, it does. I think that “ceart” means “just” or “very” in this context.
“Maith go Leor” is sometimes spelled “mongalore,” which is closer to the English pronunciation. “Maith go Leor” means “doing alright” in eastern parts of Ireland; it has a connotation closer to “tipsy” in western parts. (from Dolan’s Dictionary of Hiberno-English)
So if you wanted to be clever this weekend, you could say, for example, “D’ya tink Dave was a bit mongalore last night? He must have been celebrating his Bugle awards.”
Warning: Speculation
I don’t understand Irish grammar yet, but I think that the word “go” is a verb-modifier somewhat like “to” in English — as in, “I’m going to build a bench.” I’ll find some books to become better informed, but I’m swamped right now.