Se chatouiller le poireau

Literally: To tickle the leek / to polish the column

Example: “Dans cette comédie grivoise, l'expression « se chatouiller le poireau » fait rire toute la salle.” — In this bawdy comedy, the slang phrase for masturbating gets the whole audience laughing.

Origin: Almost any long straight thickish object has served French as a word for the penis, so the ways of naming this are many — peigner la girafe works off the animal's neck. The leek is in Rabelais, in Pantagruel, though not yet explicitly: a vigorous old man is comme le poireau, la tête blanche et la queue verte, white-headed and green-tailed, vert here meaning lively or ribald. Only in the 18th century does the vegetable plainly stand for the organ, which is also when se dégourdir le poireau appears, of a man returning to use after a long abstinence. The column is precisely dated: Cellard and Rey put its arrival as a phallic symbol at 1820, when the Vendôme column went up in Paris and its opponents took to calling it a bronze phallus. The polishing motion supplied the rest.