A member of the Irish Travellers
who funds his or her lifestyle through fraud, mostly committed against the elderly. They typically offer to do home improvement work at an attractive price, then either run off with the money, or if they actually do the work, do a substandard job and then demand more money. Female yonks enjoy five finger discounts
at department stores, attempting to exchange the stolen goods for cash.
Then they all go out for Sushi with their ill gained loot, parading their "lackeen
" toddler daughters around like Jon Benet Ramsey.
yonk: "I noticed your drive-way needs paving. I was doing work up the street and have plenty left over for another job. I'll only charge you forty dollars..."
you: Fuck off you yonk bastard!