Irish slang is becoming quite a worldwide phenomenon with several books recently on the subject. Here are some examples

Acting the Maggot
Acting in a lighthearted, non-serious manner
As in: Would you ever stop acting the maggot and peel those spuds, like?

Aul Wan
Your own, or anyone else's, mother
As in: Is that your aul wan waiting for you at the school gate?

Bettys
Women
As in: Did you ever see so many Betty's in the one place, like? We're laughing.

Beak
Mouth
As in: If he doesn't stop singing "Ice Ice Baby," soon I'm going to hit him a clatter on the beak.

Bogger
A rural person (offensive)
As in: There must be a new tractor show. The town's overrun with boggers, like.

Chancer
A person who continually pushes their luck
As in: That government minister's a right fecking chancer.

Clatter
To punch
As in: I'll give you such a clatter on the gob you'll need a team of nurses, like.

Cute Hoor
A highly manipulative person
As in: He's some cute hoor that lad, isn't he? Started off in the mail room and now he's running the company.

Dose
An individual of little personal charm
As in: Jaysus, your cousin Michael's an awful dose. Where did you find him?

Eejit
Idiot
As in: You're an awful fecking eject, do you know that?

Feck
Hiberno corruption of the Anglo Saxonism
As in: Feck me, lads. Get to feck. Who's that big fecker?

Jacks
Restroom
As in: Hi, where's the jacks? I'm busting.

Mingin'
Offensive, displeasing to the eye or nose
As in: You couldn't eat that there fish, Majella, it's mingin'

Plastered
Intoxicated
As in: Your man over there's plastered, don't let him drive anyone home.

Savage
Awful
As in: Your man got up and sang a wee song then and it was savage altogether.

Scald
Tea
As in: Any chance of a cup of scald there missus?

Sky Pilot
Absurdist catch-all insult
As in: Away to hell you feckin' sky pilot!

Tool
Dolt, foolish person
As in: Your brother Aidan is a complete feckin' tool.