The quantity of numbered minor planets is now approaching half a million. Together with this Addendum, the sixth edition of the Dictionary of Minor Planet Names, which is the IAU's official reference for the field, now covers more than 19,000 named minor planets. In addition to being of practical value for identification purposes, the Dictionary of Minor Planet Names provides authoritative information about the basis for the rich and colorful variety of ingenious names, from heavenly goddesses to artists, from scientists to Nobel laureates, from historical or political figures to ordinary women and men, from mountains to buildings, as well as a variety of compound terms and curiosities. This Addendum to the 6th edition of the Dictionary of Minor Planet Names adds approximately 2200 entries. It also contains many corrections, revisions and updates to the entries published in earlier editions. This work is an abundant source of information for anyone interested in minor planets and who enjoys reading about the people and things minor planets commemorate.