What term describes something "alive" with a "brain"?

Plants are considered 'living' but without a brain, so alive or life don't work.

Fish have brains, jellyfish don't.

For my example sentence, I will be using a hypothetical viewpoint:

I don't just want a salad cause I am not really a vegan. I just won't eat any [term], I will take jellyfish with the starfish rolls rice bowl instead, thanks.
— person 1

Yea well, with animals, I only eat [term]. You can have the jellyfish all to yourself.
— person 2

[term] or not, I don't eat animals.
— the vegan

Please help me find the word to say "This living thing has a brain".

Thanks for any input even if it is not a one word answer I am looking for.

  • 1
    Are planets 'living things' in that sense? Many 'lower animals' don't have a brain as such, though. I thought of encephalous, but apparently that means 'having a head'. Oct 22, 2022 at 8:14
  • 1
    The duplicate asks a different question. Voting to reopen.
    – jimm101
    Oct 23, 2022 at 16:10
  • 1
    @EdwinAshworth that is a different question. I dont care if it is smart or self aware or anything just that it has a brain. one can have a brain and be alive but still brain dead. for example this guy: ncbi.nlm.nih.gov/pmc/articles/PMC5102206/….
    – CrandellWS
    Oct 24, 2022 at 19:56
  • 3
    I think the biggest problem is that the number of animals that have some sort of nervous system feature that resembles a brain is enormous. There are just not that many animals that don't have a brain of some sort. There's not a sharp dividing line between having a brain and not having a brain, it's more a matter of deciding how big a bundle of ganglions has to be before you can call it a brain.
    – barbecue
    Oct 24, 2022 at 21:44
  • 1
    Plants are acephalous for me. :) Call someone that and check their reaction.
    – Lambie
    Oct 25, 2022 at 16:08

4 Answers 4


There isn't a distinct terminology to distinguish animals with a brain and animals without a brain in biology/zoology/neuroscience and also in culinary world per your context. It is not always clear if we can call the concentration of nervous tissue a brain in some smaller animals and there is sometimes no consensus also, like in the case of planarians (a type of flatworm) where the mass of nervous tissue they possess is called a simple brain by some experts or cerebral ganglion by others. Additionally, almost all animals have a brain with a few exceptions like jellyfish, starfish, sea urchins, sea cucumbers, clams, oysters, sea anemones, sea sponges, men-of-war, sea lilies, sea squirts, corals. Sponges are one of the most exceptional animals as they have no brain and no nervous system at all. The closest common distinction related to nervous system is vertebrates (animals that have a backbone/spine) vs. invertebrates (animals that don't have a backbone/spine); although it is not just about brain. Invertebrates can have a brain too. Merriam-Webster has a detailed definition of a vertebrate:

any of a subphylum (Vertebrata) of chordates that comprises animals (such as mammals, birds, reptiles, amphibians, and fishes) typically having a bony or cartilaginous spinal column which replaces the notochord, a distinct head containing a brain which arises as an enlarged part of the nerve cord, and an internal usually bony skeleton and that includes some primitive forms (such as lampreys) in which the spinal column is absent and the notochord persists throughout life

Wikipedia has this relevant sentence in Vertebrate article also:

The vertebrates are the only chordate group with neural cephalisation, the concentration of brain functions in the head.

Having said that, I was checking if there is a term starting with encephalo- as it is the combining form of words having to do with the brain, from ancient Greek ἐγκέϕαλος 'encephalos' brain. I couldn't find a relevant word in OED and I thought encephalous could work but it has a very specific usage in zoology:

Of molluscs: Possessing a distinct head; belonging to the Encephala n. - OED

There is also Latin cerebro-, combining form of cerebrum 'brain' but I couldn't find a relevant word with this form also. For example, cerebrous is not listed in dictionaries and cerebrate has a very different meaning.

Surprisingly, I've found two rare words in Wordnik citing The Century Dictionary with relevant definitions; although these terms are not really used in science and they appear to be very rare words, so most people would not understand:

encephalata Animals which have an encephalon, as all cranial vertebrates: nearly synonymous with Vertebrata, and exactly with Craniota.

encephalate Having an encephalon, or a brain and skull; cranial, as a vertebrate.

  • men-of-war... LMAO oh my lets no go there please delete that. But this is the best answer so far thank you.
    – CrandellWS
    Oct 25, 2022 at 22:02
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    " Portuguese man o' war, also known as the man-of-war, is a marine hydrozoan found in the Atlantic Ocean and the Indian Ocean." - Wikipedia
    – ermanen
    Oct 26, 2022 at 8:23
  • interesting... well I thought it was a joke. thanks for clarifying
    – CrandellWS
    Oct 26, 2022 at 11:46

There’s plenty of references online to brainless animals eg. from Science

One of the first brainless creatures shown to sleep, the upside-down jellyfish, pulses its bell more slowly at night than in the day.

It’s hard to find references to the opposite. Here’s a few but they seem less “standard”.

Largest Brain Animal
Many mammals have the largest brain size compared to their body size. Some mammals have the largest brain size, as given below;
Sperm Whale. […].
killer whale. […].
Elephant. […].

Large-Brained Animal Models of Huntington’s Disease: Sheep.
The limitations of using small-brained rodents to model diseases that affect large-brain humans are becoming increasingly obvious as novel therapies emerge.

  • 2
    Brained is possible, although words such as brained, footed, eyed, etc are commoner in compounds like large-brained, two-footed, than stand-alone, and brained also has a slang meaning, "hit on the head", but still it's probably the best answer there is. Brainless is fine.
    – Stuart F
    Oct 24, 2022 at 8:58

Sentient: (antonym - Insentient / non-sentient)

OED sentient, adj. and n.

1.a. That feels or is capable of feeling; having the power or function of sensation or of perception by the senses.

1632 Guillim's Display of Heraldrie (ed. 2) iii. xxiv. 250
Forasmuch as God would that the faculties both intelligent and sentient should predominate in the head [etc.].

1879 G. H. Lewes Probl. Life & Mind 3rd Ser. I. 8 We can define it [the relation of Mind to Life] by analytically distinguishing certain functions as sentient from other functions as nutrient.

The word "sentient" implies that there is a brain in which feelings, perceptions etc, are processed.

The Politics of Species: Reshaping Our Relationships with Other Animals edited by Raymond Corbey, Annette Lanjouw

Sentience, a capacity to experience, is necessary and sufficient for rights. Why? By definition, sentient beings can experience suffering and well-being. Also, sentient beings lose all opportunity for pleasant experiences when they die. (Insentient things such as plants don’t lose anything when they die because they’re completely unaware whether alive or dead. They have moral relevance oniy insofar as they affect sentient beings.) Therefore, all sentient beings need legal protection against humans who would needlessly deprive them of their well-being or lives. The whole point of laws is to protect interests. All (and only) sentient beings have interests.

  • That's a stretch. The last quote mixes up sentiment and consciousness in my eyes.
    – Skobo Do
    Oct 25, 2022 at 11:23
  • There seems to be quite a distance between sentiment and sentient.
    – Greybeard
    Oct 25, 2022 at 15:55
  • Was a typo. Still, I think the quote is mixing up those.
    – Skobo Do
    Oct 25, 2022 at 16:08

How about "self-aware"? To be aware of the own existence is a direct result of having a brain.

  • 3
    Is everything with a brain self-aware? Oct 25, 2022 at 7:59
  • @KillingTime: this is difficult to determine, because we can't ask animals directly about what they feel. What we do know, though, is that without a brain (i.e. as in plants) self-awareness is not possible at all.
    – bakunin
    Oct 25, 2022 at 8:07

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