Is there a word for beings that will eat other Sentient beings? [closed]

I'm not aware of any such word. While of course people speculate on the existence of sentient life on other planets (or on this planet), we are not in contact with any such beings or even aware of the existence of any specific such beings, so it is not surprising that we would not have words to describe many potential aspects of interaction with them. (Well, I suppose if people really are being kidnapped by aliens in flying saucers, they are in contact with such beings. But the general public isn't.)

I don't know that it's clear that people generally don't eat dolphins because of perceptions of their intelligence. The Inuit in Alaska and some Japanese eat dolphin meat; most people from Europe and European-derived cultures don't. Americans don't eat dogs or cats but people in other countries do. Most people I know find the idea of eating spiders and snakes repulsive, and I don't think the reasons have anything to do with a theory or belief that spiders and snakes are highly intelligent.

Sentience, intelligence, and language are not all directly related, and their intersections are largely the realm of philosophers, cognitive scientists, and sci-fi enthusiasts. Singer denies that sentience is relevant in moral philosophy, and sentience itself can be variously defined: there is a Buddhist concept, which differs from the Catholic concept, which differs from Freitas' concept, which differs from Roddenberry's. I would also dispute that dietary taboos are based on the intelligence of the meat. The domestic pig is "smarter" than the domestic dog, but found in many more cultures' cuisines. And there's more I would object to, but that's all beyond the scope of this site. Let us say you mean human or human-like, comprising whatever qualities your preferred philosophical and moral system may identify as making a Wookiee, a goldfish, or SkyNet "human enough," be it responsive interaction, moral agency, bipedalism, or an appreciation for green Orion women.

Humanoid is a morphological term, and sentient, conscious, cognizant, or sapient are all philosophically vague. In English, those entities who possess "human-ness" are broadly beings (e.g. human beings, but also angels, mermaids, Mrs. Whatsit, or laboratory rabbits to various subsets of the population). That would be a tricky root to use, however. Para-anthropic might be better, or we could borrow a term from a specific tradition or discipline, like sem chen or sattva.

English words for describing an organism based on its dietary consumption fall mostly into three camps:

• the -vore, from the Latin vorare, "to devour": insectivore, saprovore, omnivore
• the -phage, via Latin from ancient Greek φαγεῖν, "to eat": myrmecophage, saprophage, autocoprophage
• the -eater, the agent noun of to eat: anteater, lotus eater, man-eater.

(Cannibal is an anglicisation of a hispanicization of a tainoization of Carib, rather than a term inherited or constructed from roots).

And that should give you room to coin a term to your liking: sentientivore, paraanthropophage, sattva-eater, and so on.