Entry 1 sense Webster, 1913 Cannibalism /kăn'-əb-əl-ĭzˌ-əm/ · Can·ni·bal·ism · IPA /ˈkanɪbəlɪz(ə)m/ 01 n. The act or practice of eating human flesh by mankind. Hence; Murderous cruelty; barbarity. 1. The act or practice of eating human flesh by mankind. Hence; Murderous cruelty; barbarity.