Graisser la patte

Literally: To grease the paw

Example: “Pour obtenir son permis de construire, il aurait graissé la patte d'un fonctionnaire.” — To get his building permit, he allegedly greased an official's palm.

English equivalent: To grease someone's palm

Origin: Not lubrication. The grease is fat, and fat has long stood for profit — a well-fed man being the visible sign of one who can afford to eat. Graisser therefore marks gain, and specifically ill-gotten gain, which is the same figure at work in the older engraisser les mains à quelqu'un, to fatten someone's hands. The expression dates from the 17th century; the 14th said oindre la paume, to anoint the palm, and the step from anointing to greasing is a short one. The patte rather than the main is the insult carried along with the money — the hand receiving it is an animal's.