Douglas Harper's Etymology Dictionary
"penis," 1969, from Yiddish shlang, literally "snake."
Wiktionary
n. (context vulgar slang English) A penis.
Usage examples of "schlong".
Cock, sword, member, dick, wiener, knob, meat, chopper, sausage, prick, one-eyed trouser snake, pork sword, schlong, donger, winkle--the list is, if not endless, then at least impressively long.
Foley catheter was running yellow stuff out of his vermilion-tipped schlong, which lay across his lap like a pet snake.
I told her over the phone, she ought to get herself a rubber schlong so she can whip it around and spray trees or whatever she wants till she gets it out of her system.
By the way, the guy is supposed to have a schlong on him like a fifteen-inch chunk of flex pipe.
And if a pointy-bearded Director of Photography got grazed across the ankle, if a towel-boy or a makeup-girl lost a finger or two, if Charity Divine had her hairstyle scorched or Schlong Gielgud stopped one in the rump who cared?
You invited Rolf to a gangbang because he showed off his big schlong and you found him acceptable.
First he had thought he was going to puke, then he thought he might die, then he had found himself inside one of those kaleidoscopes, then they spent forever squatting on the bed and staring at each other to the tune of some kind of sci-fi flic music, during all of which the treacherous schlong which had gotten him into this mess in the first place remained limp as the proverbial wet noodle.