German. Literally, "pig stick." Utilized in the movie "Young Frankenstein" to allude to the penis. Dr. Frankenstein (Gene Wilder) is discussing how all the parts of the monster would need to be to "artificially or congenitally englarged." Inga (Teri Garr), the doctor's assistant, gets a strange look on her face and says, "oof...he would have an enormous schweinstock!" To which the Doctor replies with, "Well, that goes without saying..."
"He's going to be very popular," pipes in Igor (Marty Feldman).
What a schweinstock that guy has - he must have to tuck it into his sock!