Using all letters

                                                                            autodidact

                                                                           autodidactic

                                                                          The other words:

                                                                              acacia

                                                                              acadia

                                                                              acidic

                                                                             acidotic

                                                                              addict

                                                                               attic

                                                                               audio

                                                                               audit

                                                                               cacti

                                                                              cactoid

                                                                              cicada

                                                                               coati

                                                                               cocci

                                                                              dacoit

                                                                              diadic

                                                                               dicot

                                                                               dicta

                                                                             didactic

                                                                               ditto

                                                                               idiot

                                                                              idiotic

                                                                              outdid

                                                                               tacit

                                                                              tactic

                                                                              tactoid

                                                                              tictac

                                                                              tictoc

                                                                               tutti