What does it mean to be a cannibal? The O.E.D. define the term "cannibal" as "a person who eats the flesh of other human beings." Note that the definition here does not include organs, blood, tissue, bone, cartilage, bodily fluids, or anything else I might have missed. The first definition of "flesh" in the O.E.D. notes, "the soft substance in the body consisting of muscle tissue and fat," whereas the fourth sense of the term "(the flesh)" is defined as "the physicality of the human body as contrasted with the mind or the soul." The latter allows for flesh to be generally taken as the corporeal and physical parts of a human being rather than the existential or metaphysical parts. This would mean that everything, not just the meat and skin of a human, is flesh. Yet, it is not the primary definition of the term as skin, muscle tissue, and fat is.
Perhaps it is important to acknowledge the distinction made here so as to disallow for the ingestion of one's one phlegm or the bodily fluids of one's self or others as cannibalism. If the definition included every part and fluid of a being then children who pick their nose and eat the contents discovered within may technically be labeled cannibals since they are consuming a part of the human body. I take the definition to this extreme to show that defining cannibalism is not as straightforward as one might assume without further contemplation and inquiry. Another example might be the question of drinking human blood. Is that vampirism and not cannibalism because it's blood? Blood is a part of the body; without blood circulating through flesh (muscle, tissue, fat), flesh would wither and die. If you cut your finger and suck up the blood in order to prevent it from dripping on your fancy new shirt is that cannibalism? Vampirism? Both?
Let's move on to flesh now. Eating another human being's flesh is cannibalism. Biting your nails or engaging in the rather gross practice of picking your scabs or dry skin and ingesting it is not. Why? Because it is your own body. According to the above definitions one can costume one's own body and not be a cannibal.
Okay. So I think despite all these exceptions I bring up it is fair to say that eating the flesh of another human being is definitely cannibalism. But what about consuming another person's thoughts, their personae, emotions? How about eating somebody's soul? Is that cannibalism? Stay tuned. I hope to figure this out through both research and poetry. Yay!