Keywords: either, whether, which
Sign Definition
As a Noun
                                            1.  Each of two things. English = either one.
                                          
                                          
                                        As Modifier
                                            1.  Used in front of the first of two alternatives, when you are stating the only possibilities or choices that there are. English = either, whether.
                                          
                                          
                                         
                  
                      