Diplomatic meaning : The science of diplomas, or the art of deciphering ancient writings and determining their age, authenticity, etc.; paleography. Concerning the relationships between the governments of countries. Exhibiting diplomacy; exercising tact or courtesy; using discussion to avoid hard feelings, fights or arguments. Describing a publication of a text which follows a single basic manuscript, but with variants in other manuscripts noted in the critical apparatus Relating to diplomatics, or the study of old texts; paleographic.