What “Ginnal” means
A ginnal is a con artist, trickster or smooth talker who cheats people. The word warns you not to trust someone's sweet talk or too-good deals.
Examples
Him a ginnal — him love pay wid big bill an confuse yuh wid di change.
He's a con man — he loves to pay with big bills and confuse you with the change.
Mind him — him a ginnal
Watch out, he's a con man
How to use it
Common in everyday talk, especially about markets, money and deals. It's an insult, so calling someone a ginnal to their face is fighting talk.