This sign is generally done with one hand and means to "spend money."
To do it right, pretend you've got a quarter under your thumb. As you move your
hand forward, slide the quarter forward and off your fingers as if sliding
it into a vending machine.)
This is a great sign.
I recall watching a young man talk about his car. That car was his
pride and joy. One complaint he had though was it was like a baby. He
had to keep "feeding" it. This is the sign he used for "feeding." What
he meant was he had to keep spending a lot of money on it.
This same sign can be used to mean "nourish."