Can zombies have meaningful lives? If not, does that mean a meaningful life is "like" something?
It depends what you mean with meaningful lives. Assuming that zombies do not have emotions and thoughts, but are functioning like an organic robot.
(1) They can have meaningful lives when they are useful in a way (are there helpful zombies?). In the same way machines can have a meaningful existence for humans.
(2) If you asking about meaningful lives in a personal way you have a different answer. Meaning is a difficult subject, but when we talk about meaning of life concepts as (self)consciousness, caring (about something/ the world) and judgements are involved. These are all processes that involve emotion and thought. So to bad for the zombies.
If you want to know more about this subject I suggest you read some articles about dementia and meaningful lives.
I think this question should be examined from the sociological perspective, as well as the physio-biological.
If one equates meaning in life to rational thought then zombies, or any animal other than humans and dolphins I suppose, would have little chance to find meaning to their lives aside from simply satisfying basic instincts.
However, we can give meaning to their lives, assuming our society is around to do so... Consider, on the precipice of an outbreak, the first zombie to be filmed. The video would go viral (pun intended,) and the various news media outlets would plaster it all over the place. The zombie would probably be named. It's be recognizable in suburban households; it'd be famous!!
In that vein, the life of zombie that tragically eviscerates a political candidate, or pop icon, in front of a national audience would hold meaning in the lives of the witnesses. One will not likely forget the face of the zombie that kills a dear family member in front of him/her, again assuming that person ultimately makes it out of the confrontation...
Now, I realize none of this holds water with the zombie as an individual or a species. But, consider the parable of the 100th monkey. The 100th zombie, in this case, that, say, discovers that the braaaaiiiinnnnsss are the tastiest part of their prey, may unlock an evolutionary domino effect that alters the behavior of the entire species... In terms of science, this is a very meaningful event - even though it is one of which neither the individual nor the species is cognizant.