The Irish have their own language, sometimes impossible for outsiders to understand.
Here are just some examples of Irishspeak or slang.

1.“Merciful hour look at the state of him”
Translated: “Oh my God he is in an awful way”

2.“How are you me oul segocia”
A term of endearment Me Oul Segocia is usually Dublinese for “me old pal”

3.”The craic was 90”
“The fun and games were the best ever.”
No one knows where the 90 came from except it appeared in a Christy Moore song. ”The Crack was 90 in the Isle of Man”
The craic is a Gaelic term borrowed from the English word crack

4. “He was completely locked/langered/pissed/elephants”
He was completely drunk,loaded, pissed
(They say the eskimos have thirty words for snow because it is so important to them, the Irish must have 100 for drink/drunk)

5. “Cat and cat malogen” as in “That’s cat or that’s cat malogen altogether.”
It means that is very bad or terrible altogether. No earthly idea where the phrase comes from.

6.”Sure it’s grand altogether”
Everything is just fine and dandy. The word ‘grand’  is used a lot in Ireland.

7.”Ask me arse”
Go away,don’t be bothering me. No prizes for guessing where it came from

8. “Feck off”
Milder form of f.. off, used a lot by nuns and priests

9.”He ate my head off”
He complained bitterly to me, was disgusted with me

10. “She’s a Lady Muck”
A very stuck up woman