Using all letters

                                                                            autodidact

                                                                           autodidactic

                                                                          The other words:

                                                                              acacia

                                                                              acadia

                                                                              acidic

                                                                             acidotic

                                                                              addict

                                                                              adduct

                                                                               attic

                                                                               cacao

                                                                               cacti

                                                                              cactoid

                                                                              cicada

                                                                               coact

                                                                               coati

                                                                               cocci

                                                                               cocoa

                                                                               cotta

                                                                              cutout

                                                                              dacoit

                                                                              diadic

                                                                               dicot

                                                                               dicta

                                                                             didactic

                                                                               ducat

                                                                              idiotic

                                                                               octad

                                                                               tacit

                                                                              tactic

                                                                              tactoid

                                                                              tictac

                                                                              tictoc

                                                                              toccata