Irish Slang

Must admit that while I'm a very sweary person, I'm not comfortable trying to translate words like spa, mong etc. But anyway, moving on -

Mate - a chara / a stócaigh / a bhodaigh (latter two only for use with male friends!)

legend - wouldn't be directly translated in the meaning of "your man's a legend", but laoch means hero and is often used in that sense. "Is tú mo laoch" would more or less equate to "you're a legend".

getting locked - Irish words and phrases to do with drink are like Eskimos having terms relating to snow - there's loads to choose from, but a very common one that's probably closest in meaning is "bhí mé stiúgadh ólta" (dying drunk). Ar an drabhlás = on the p*ss. Dearg ar meisce = completely p*ssed. Tinneas póite = hangover.

get the shift - hmm, there are a few phrases I've heard but I can only think of "póg" at the minute. I once heard something like "bhí mo theanga súite amach as mo chloigeann (the tongue was sucked out of my head), but I must admit that sounds more like a description of poor technique than a commonly used phrase ...
"Bualadh craiceann" would more or less translate "riding" (literally "skin-slapping"), and "bualadh feola" is what you might end up doing if you don't make it that far. If you want to actually call someone a w*nker, you say "buailteoir feola". (NB a bra is a cíochbheart - literally, a package of tits!). Magairlí = balls.
As well as being a word to mean party, festival, etc, "feis" means f*ck - as in "feisigh leat" (go f*ck yourself). Interestingly, the word for wedding, bainis, is derived from "bean fheis". Not a lot of people know that ....

LOL - GOA (gáire os ard)

Have a gander here

http://www.insults.net/html/swear/irish.html