Chancer

n.

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

A dodgy, opportunistic rogue who cannot be trusted.

In use

Yer man is some chancer, flogging dodgy books out of the boot of his car.

Posh English

That gentleman is an incorrigible opportunist, peddling literature of dubious provenance from the luggage compartment of his motorcar.

Same phrase, other counties