I've definitely come across the word "grifter" as a synonym for someone who defrauds people ("marks") in en_US. "Grit" is a perfectly valid en_GB word meaning

I've definitely come across the word "grifter" as a synonym for someone who defrauds people ("marks") in en_US. "Grit" is a perfectly valid en_GB word meaning the same (enduring hardship.)