diplomatic

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Of, relating to, or involving diplomacy or diplomats.
• adjective Using or marked by tact and sensitivity in dealing with others.
• adjective Of or relating to diplomatics.
• adjective Being an exact copy of the original.

from The Century Dictionary.

• Pertaining to diplomas or diplomatics.
• Pertaining to or of the nature of diplomacy; concerned with the management of international relations: as, a diplomatic agent.
• Skilled in the art of diplomacy; artful in negotiation or intercourse of any kind; politic in conduct.
• noun A minister, an official agent, or an envoy to a foreign court; a diplomat.

from the GNU version of the Collaborative International Dictionary of English.

• noun A minister, official agent, or envoy to a foreign court; a diplomatist.
• adjective Pertaining to diplomacy; relating to the foreign ministers at a court, who are called the diplomatic body.
• adjective Characterized by tact and shrewdness; dexterous; artful.
• adjective Pertaining to diplomatics; paleographic.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Concerning the relationships between the governments of countries.
• adjective Exhibiting diplomacy; exercising tact or courtesy; using discussion to avoid hard feelings, fights or arguments.
• adjective describing a publication of a text which follows a single basic manuscript, but with variants in other manuscripts noted in the critical apparatus
• noun The science of diplomas, or the art of deciphering ancient writings and determining their age, authenticity, etc.; paleography.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective using or marked by tact in dealing with sensitive matters or people
• adjective relating to or characteristic of diplomacy