Latchico

v.

Heard in Cork, Kerry, Antrim, Clare, Roscommon, Tyrone and Wexford

A fool or idiot; originally one who sniffs bicycle seats after women have dismounted.

In use

What are ya at ya latchico" "Gway ya latchico

Posh English

What on earth are you doing, you complete idiot?

Same phrase, other counties