Schnook (noun)

1. A naive, gullible, or easily manipulated person.
2. A person who is easily taken advantage of, especially in a financial or business context.

Origin:

It is believed to have originated from yiddish word "shnuk" meaning a simpleton, a sucker, or a naive person.

Examples:

1. He was such a schnook that he fell for the oldest trick in the book.
2. The schnook was duped by the con artist and lost all of his money.
3. He was always getting taken advantage of by schnooks who knew how to take advantage of his good nature.
4. The schnook was taken in by the smooth-talking salesman and bought the overpriced car.
5. He was considered a schnook for being so easily taken in by the obvious scam.