Lash

n.

Heard in Tipperary, Kilkenny, Cork, Cavan, Dublin, Waterford and Down

An act of urination.

In use

I'll be back in a sec, I ahve to go for a slash." "Im burstin, im goin for a lash.

Posh English

I shall return in a moment. I simply must visit the lavatory. I am bursting and must visit the lavatory.

Same phrase, other counties