Assuming you are referring to the abbreviations that typically follow years, A.D. stands for anno domini, which means "in the year of our lord" in Latin, while B.C. stands for "before Christ."
BC or B.C. might mean "Before Christ" if in reference to dates. Modern scientific term is BCE "Before Current Era". In geography, Baja California, a state in Mexico; or British Columbia, a province...
CBS, the television station, used to stand for Central Broadcasting System. In modern companies, sometimes they take away the original meaning and just keep the letters. KFC did this, and they are no...