the process of masturbating immediately after your hand/arm has become numb either naturally, from a shot, or from sitting on your hand on purpose. Its main purpose is to make it feel like you're not jacking off by yourself in a dark room watching a porno that you've already seen dozens of times.

Also mentioned on the Comedy Central tv show, "Ugly Americans"
-Dude, have you ever done the Phantom Spank?

-What's that?

-Are you kidding?! It's only the best masturbation method ever created!
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when a man saws off his arm and then uses said arm to masterbate to lizzy mcguire
i just walked in on clint performing the phantom spank! said whoopi goldberg
by whoopiegoldberg April 15, 2010
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