Fans of The Walking Dead long ago noticed that the characters in the popular television show never refer to the flesh-eating creatures they fight so often, as zombies. While there have been plenty of guesses as to why this is the case, the franchise's creator Robert Kirkman finally explained exactly why all of The Walking Dead shows avoid the name.
Kirkman first created The Walking Dead as a comic book that was supposed to serve as a continuation of the stories that George A. Romero introduced to audiences in the 1960s. Romero's Living Dead franchise was the first that really coined the term zombies and for a time, Kirkman was paying homage with his comics. Eventually, he decided to bring his story into modern times and it's here where The Walking Dead became a household name on television and soon; movies.
In the latest installment of "Cutting Room Floor with Robert Kirkman" published in The Walking Dead DELUXE #30, the creator explained that originally, his characters did refer to the zombies as zombies. He then moved away from that term and started having his characters call the undead Lurkers, Roamers, and Walkers. Over the course of the comic book run, the writer decided to become a bit more consistent and Walker turned into the most often used term.
Kirkman also explained that it was Frank Darabont that first decided that in The Walking Dead television series, they would never be referred to as zombies. Darabont thought that the word zombie wouldn't exist in the world of The Walking Dead since the works of Romero didn't exist in this particular world.
Kirkman and Darabont felt that in order for the zombie apocalypse to really take hold and end the world, people would have to not know very specific ways to kill them, such as just shooting them in the head. At first, there would have to be some trial and many errors as people figured out exactly how to stop what was happening. Confusion over what the undead were was essential in making sure that people were succumbing to the Walkers, especially since they aren't the fast-moving zombies that have been featured in more recent movies centered on the genre.
It's long been a fan theory that The Walking Dead universe didn't have Romero's stories precisely because it seemed odd that there were so many other names for the monsters. While the main show refers to them as Walkers, Fear the Walking Dead characters refer to them as The Infected, and The Walking Dead: World Beyond refers to them as Empties.
Source: ComicBook.com