diplomacy

Where it comes from

English diplomacy came from French diplomatie, formed from diplomatique. The family ultimately reaches Greek diploma, something doubled or folded, which became a term for an official document granting a right or privilege.

How the meaning developed

Diplomatic first concerned charters and official documents, and diplomatics still names their scholarly study. Because such documents included treaties and credentials used in relations between states, the family shifted toward envoys and international negotiation; tactful private dealings followed by extension.