Douceur [doo-SUR]
(n.)
- A gratuity; tip.
- A conciliatory gift or bribe.
- Sweetness or agreeableness.

Middle English from Middle French "douceur" (sweetness/pleasantness) from Old French "doucet" diminutive of "doux" (sweet) from earlier "dulz" from Latin "dulcis" (sweet) + French suffix “-eur”.

Used in a sentence:
“Don’t worry, I slipped the host a little douceur, to get the best table.”