Easy isn't it? everyone knows what "eat" means.

Except I'm not sure there is agreement. We probably all agree that to eat, one puts food in the mouth, masticate (chew) and swallow. But is even this true? It works for any animal with a mouth. But if we look at protozoans (unicelled organisms similar to animals, they were previously classified as animals, until 2005), they have no mouths. So when they take in food, is it incorrect to say they "eat", so are we required to say they "consume" or "injest"? There's a word, "zoophagy", which means "to eat meat". There are fungi that are zoophagous, so, by definition, those fungi "eat meat". But fungi don't have mouths implying that eating doesn't require a mouth. Then, when a fungus is zoophagous, it can only obtain food by inserting a part of itself (a hypha, a bit like a root) into the food source (an animal) and digesting it, then to absorb the resultant soup of nutrients. Therefore, zoophagy, "to eat meat", seems to require digestion to take place (one of the most common uses of the term "zoophagy" is with regard to fungi, so it seems that to eat without having a mouth is a common understanding). So, does eat' include digestion or exclude it? I've checked the Oxford Dictionaries (OED, COED) and they do not help. While they seem to define eat well, they give no information to prove their definition is valid (it excludes digestion). Certainly, OEDs would exclude digestion so that means they would require that we do not apply the term "eat" to protozoa or fungi (but scientists do).

So, this simple little question is in fact very complicated. What does "eat" mean?

Thanks if you're brave enough to have a really good stab at this. All logical answers and appropriate citations appreciatively received. Happy to be guided from philosophical perspective (logic) or from a pure linguistic perspective or both.

(PS My current opinion as a non-linguist is that, based on fungi, "to eat" must include digestion and needn't involve a mouth, mastication or swallowing. Please do not let my position bias your thoughts.)


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    The first (of many) definitions for eat in thefreedictionary is To take into the body by the mouth for digestion or absorption. But even that is just the first of three subsections for that definition, where the second is To take in and absorb as food (example usages a plant that eats insects; a cell that eats bacteria). I don't think this question is really about English at all; it's just an invitation to discuss the scope of concepts. – FumbleFingers Apr 9 '16 at 20:33
  • Instead of looking in the OED, try a biology textbook. The word evolved (from OE, etan) long befor people started studying microscopic Gummi worms and compounding sesquipedalian terms for how they nourish themselves. I would surmise that those who can't spell, pronounce, or care less about the particular arcane processes through which microinvertebrates get their lunch simply call it "eating" and have done with it. (As I watch my feline housemate attempt to catabolize a mouse...) – Rob_Ster Apr 9 '16 at 20:46
  • I have previously consulted a host of biology books. The problem is that how a word began being used does not necessarily prevent its use being changed; as human experience discovers things that people did not know of when (modern) language evolved. Scientists use "eat" (not consume and not, as yet, catabolise - though one can wish) when referring to not just animals but protozoans and even fungi. So the meaning is a mess, thus my question. (Hope you cat enjoyed its catabolism). – paulindr Apr 9 '16 at 20:58
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    And ... no, it really is a question about English and I honestly don't have time for a discussion of "concepts". I'm looking for any linguistic or logical argument that prevents "eat" from applying to digestion or creatures without mouths. Just your two replies (gratefully received) suggest no such arguments exist, which conflicts with a one scientific view that i read 9which caused my question). – paulindr Apr 9 '16 at 21:19
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    I don't think "eat" automatically includes "to digest". I would say that "eat" generically means "to feed upon". "Ingest" is to take something in, in bigger particles than absorb. (Swallowing is ingesting; one ingests pills, one doesn't usually eat them.) – anongoodnurse Apr 9 '16 at 21:19

You are playing with two different meanings of eat:

To consume

To envelop

Which is meant depends on context. Sometimes both. Sometimes only one. Sometimes neither. I'd like to point out that you are underestimating eat. It can have a lot more meanings than these two. Here's a few in bold:




verb: eat; 3rd person present: eats; past tense: ate; gerund or present participle: eating; past participle: eaten

  1. put (food) into the mouth and chew and swallow it.

"he was eating a hot dog"

synonyms: consume, devour, ingest, partake of; gobble (up/down), bolt (down), wolf (down); swallow, chew, munch, chomp; informalguzzle, nosh, put away, chow down on, tuck into, demolish, dispose of, polish off, pig out on, scarf (down)

"we ate a hearty breakfast"

have (a meal).

"we ate dinner in a noisy cafe"

synonyms: have a meal, consume food, feed, snack; breakfast, lunch, dine; feast, banquet; informal: graze, nosh; dated: sup

"we ate at a local restaurant"

have a meal in a restaurant.

have a meal at home rather than in a restaurant.


bother; annoy.

"she knew what was eating him"

US: vulgar slang

perform fellatio or cunnilingus on (someone).

vulgar slang

perform cunnilingus or anilingus on (someone).


absorb (financial loss or cost).

noun: informal

plural noun: eats; noun: eat

  1. food or snacks.

"people would stop for soft drinks or eats"

synonyms: food, sustenance, nourishment, fare; eatables, snacks, tidbits; informal: nosh, grub, chow, vittles, chuck

"come on in for some eats"

google: eat define

You said in the comments:

I'm looking for any linguistic or logical argument that prevents "eat" from applying to digestion or creatures without mouths. Just your two replies (gratefully received) suggest no such arguments exist, which conflicts with a one scientific view that i read 9which caused my question)

I have one: context

The scientific view was likely meant to apply a disciplined definition to the word. You shouldn't take the creation of that definition as meaning you have to reread every book that features the word eat. It means in that discipline they'd like to not go around using the word eat for things that don't have mouths. A perfectly reasonable position for that discipline. Meanwhile, the English language does what it darn well pleases.

If you want us to critique the definition we need to see it in the question.

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  • You forget rust eating away at a car body, or acid eating away a piece of marble. Not to mention someone being made to "eat dirt" in a fight. Or loneliness "eating away" at a teenager. – Hot Licks Apr 9 '16 at 22:07
  • Or eating crow, eating one's heart out, eating my dust, eating your feelings, eating my time... – candied_orange Apr 9 '16 at 22:13

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