look up any word, like swoll:
Engaging the act of male masturbation in a public populated place inconspicuously and discreetly.
"Dude...check out the guy at the front of the bus, hes silent stroking man"

"Shit man, me and teeps were sitting in econ lecture, and the guy was trying to silent stroke, it was gross!"
by Rizzleeee February 09, 2009