douceur

noun4

1. •
   Sweetness of manner: agreeableness, gentleness.
2. •
   A sweetener: a gift offered to sweeten another's attitude, a tip or bribe.
3. •
   (UK) A tax break provided as an inducement to sell valuable items (especially art) to public collections rather than on the open market.
4. •
   (no longer used) Sweet speech: a compliment.