Bribes, or rather money for bribes, fees, etc.
“In Ireland the machinery of a political movement will not work unless there is plenty of palm-oil to prevent friction.”—Irish Seditions from 1792 to 1880, p. 39.
“The rich may escape with whole skins, but those without ‘palm-oilʹ have scant mercy.”—Nineteenth Century, Aug., 1892, p. 312.