The term LIKE A ZOMBIE can be summarized as 'being like an undead creature'. An undead creature is a being that has died but still appears to be alive. Zombies are a popular example of an undead creature, and the term LIKE A ZOMBIE is used to describe someone or something that is similar to a zombie in some way. This could mean that the person or thing is slow-moving, unresponsive, or has a lack of emotion.