Jackstrapolate

A portmanteau of “jack off” and “extrapolate.” The opposite of "jerkterpolate."

To imagine what an attractive younger woman will look like once she hits her prime, for purposes of masturbation.

Me: “Yo, check out that chick over there.”
Him: “Yo, but she’s too young!”
Me: “Don’t worry! I jackstrapolated her age. I’m gonna whack off to what she’ll look like in a few years.”