Chancer

n.

Heard in Kildare, Wicklow, Kilkenny, Galway, Longford, Dublin and Limerick

A person who will attempt anything, often cheekily.

In use

He's some chancer trying to get with her, and he with a girlfriend

Posh English

He is quite the opportunist attempting to woo her, and he already possessed of a sweetheart.

Same phrase, other counties