See the documentary studies, Night of the Living Dead (Romero, 1968), Day of the Dead (Romero,
1985), Dawn of the Dead (Romero, 1978), 28 Days Later (Boyle, 2002), Day of the Dead (Miner, 2008),
Dead Snow (Wirkola, 2009), et al. For an alternative interpretation on zombieism and survivor response
patterns consult Shawn of the Dead (Wright, 2004) which addresses some of the issues related to dating
during an outbreak of ZBS (see below).
...
While many people refer to “undead,” practitioners in the field of Zombie Studies and zombie advocates
such as PETZ: People for the Ethical Treatment of Zombies, and supporters of Florida Zombie Preserve,
Inc. insist that the term “undead” clearly connotes deficiency; specifically the absence of both life and
death.

I'm pretty sure their tongue is firmly planted in their collective cheek there.