Related to that, what about when a person is completely unresponsive, has no pulse, and isn't breathing is able to be revived? Do you count them as having been dead? Would you be able to call them a zombie? I remember reading before about a man who had suffered from a heart attack at a grocery store and wasn't breathing, had no pulse, and wasn't responsive. The people around him refused to give up on him and everybody took turns giving the man CPR and chest compressions until the paramedics were able to come. Thanks to all the people refusing to give up on the man, the paramedics were able to revive him and he continued to live a happy life. But this does raise some questions. Could he have been considered dead? I think so. But then he wasn't dead. What can you say about that other than the simple, 'he was brought back to life'?
Death is such a complex topic and I feel that it's become very simplified from being used repeatedly in movies and books. When I think of the concept of death (not in a bad way, just in a curious way!), all that comes to my head are images of the overdramatic movie/book deaths where the characters is slowly losing consciousness and saying their last words. Death is so much more than that, and I feel it's quite sad that it's been simplified to somebody saying their last words and closing their eyes while their head rolls to the side. Who even decided that was how death was to be portrayed? Maybe one day death will be portrayed in a different way, but either way, nobody can ever know what death is like unless they've actually died. And if they've died, unfortunately they probably won't be able to communicate with us to tell us what it's like.