Docken
A dock leaf, the big green leaf you rub on a nettle sting.
Ye got stung? Go rub a docken on it and quit yer girnin.

Shall I translate it into posh English for you, mucker?
Hello. I've just had my tea. Here it is in posh English.
You have been stung? Do rub a dock leaf upon it and cease your complaining.
Questions
What does docken mean in Ireland?
A dock leaf, the big green leaf you rub on a nettle sting.
Where in Ireland do people say docken?
People say docken in Down and Tyrone.
How do you use docken in a sentence?
“Ye got stung? Go rub a docken on it and quit yer girnin.”
Updated
Same phrase, other counties
- Down (not in the dictionary)
- Tyrone (not in the dictionary)