grease someone's palm/fist, to

grease someone's palm

 and oil someone's palm
Fig. to bribe someone. If you want to get something done around here, you have to grease someone's palm. I'd never oil a police officer's palm. That's illegal.
See also: grease, palm
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

grease someone's palm/fist, to

To bribe someone; also, to give a gratuity. This term has been around since the sixteenth century, and apparently a version of it was known even in Roman times, when Pliny the Younger called it unguentarium, translated as “ointment money” (Epistles, ca. a.d. 98). “Wyth golde and grotes they grese my hande,” wrote John Skelton (Magnyfycence, ca. 1529).
See also: grease, palm
The Dictionary of Clichés by Christine Ammer
See also:
  • palm oil
  • palm-oil
  • for (the) want of (something)
  • for want of something
  • oil up
  • lease (something) to (someone or something)
  • lease to
  • midnight
  • burn the midnight oil
  • burn the midnight oil, to