Okay... so allot of us have a scientific opinion on the dead. Let us set that aside, and assume some dumb moron read from the Necronomicon or solved the Lament Configuration.
It's obvious that the term Zombie was re-invented during the romeo era of films. Obviously the concept of a corpse resurrected through dark magik for the purposes of being a controlled and obedient servant doesn't quite fit the concept of the walker. The walkers are mindless eating machines with apparently no soul to keep the base needs of the body in check. They appear to obey no one... unless we have some unseen puppet master that will never be introduced in the comic.
So this begs the question... what variety of undead are they? If we were Occult scholars... what species of the restless would we define Homo Esurientes-Cadaueris as? Soul-less corpses? Demons trapped in dead bodies? Risen dead are a staple of all cultures. Ghoul.. Draugr... some weird form of RedCap, what superstitions would you or your family call these things?