palm oilWiktionary 原文英美词源说明In the sense of a bribe, the phrase is a punning reference to the palm of the hand and also to oil as lubricant rather than foodstuff.释义名词noun1An edible plant oil derived from the mesocarp (reddish pulp) of the fruit of the oil palm (Elaeis guineensis).2slangMoney given as a bribe.