This Addendum to the Dictionary of Minor Planet Names, fifth edition, which is the official reference for the field of the IAU, contains all newly published names from the period 2003-2005 as well as corrections and amendments to earlier editions. In total the Dictionary of Minor Planet Names now covers some 12000 named minor planets. It provides authoritative information about the basis for the rich and colorful variety of ingenious names, from heavenly goddesses to more prosaic constructions.