Hi, I'm Taylor and welcome to Crash Course Linguistics!

What is the meaning of life? Or of chair?

Or of rabbit? Well, we might not know about life, but we can easily find out what a word means. We just look it up in The Dictionary.

Episode over! Wait a sec... The first problem with relying on a dictionary to give a word meaning is that dictionaries are made by people.

And the people who write dictionaries, called lexicographers, still need some other way of figuring out what words mean. The second problem is that writing a definition isn't always the most effective way of pinning down the meaning of a word. The area of linguistics interested in meaning, and the many ways that we can describe it, is semantics. [THEME MUSIC ANIMATION].

To better understand the complexities of meaning, let's start with the humble definition, a clear and concise description of how people are using a word. Definitions are what we're used to reading in dictionaries, and help us see when one word has a certain type of relationship to another word. For example, several words can have about the same definition.

They're synonyms, like "happy" and "glad" and "joyful." Two words can also have the opposite definition. They're antonyms, like "inside" and "outside." One word can refer to a specific member of a broader category, such as "red," which is a type of "color," or "rabbit," a type of "animal". The specific word, like red and rabbit, is a hyponym.

And the broader word, like color and animal, is a hypernym. A word which is a hyponym of one word can be a hypernym of another: snowshoes are one type of rabbit, and a rabbit is a type of animal. Semantic relationships, like synonyms, antonyms, hyponyms, and hypernyms, are found across many languages, but not all languages draw semantic lines in the same place.

For example, English has the one word “know,” while Polish splits this up. It has wiem for ‘I know a fact’ and znam for ‘I know a person’. In contrast, Portuguese fazer is used where English has both "to do" and "to make".

If you look up a word in a bilingual dictionary, you'll often find more than one possible translation, and you need to know further context about how a language carves up the semantic space in order to know which translation to use. Definitions are also useful for describing how words shift their meanings over time. For example, words can become broader in their meaning. "Thing" used to refer to a council or assembly in English, but now it can be used to refer to any… thing.

Words can also become narrower in their meaning. For example "girl," used to mean "child," and now it’s more specific. And words can change meaning all together. "Nice" used to mean "ignorant," and then “silly,” then “fussy,” and now, well, “nice.” What a journey.

One driver of this language change is taboo. We use words as euphemisms to avoid saying ruder words... But then the euphemisms start getting associated with the original meaning, and so another euphemism is needed, and so on.

For example, the word "toilet" originally meant a cloth, and then a cloth used on a dressing table. Then it meant the items associated with a dressing table (like a mirror and hairbrush), and then a room containing a dressing table with a lavatory attached. Finally, people used this word to refer to the porcelain plumbing item and the room it's in, because it sounded more polite than, I dunno, craphouse? pooproom?

Now, the word “toilet” is a bit too direct in some people’s minds, and they use another euphemism for "toilet", such as a bathroom or loo. Or maybe bathroom even feels like a little too much for you, and you use a different euphemism, like "I’m just gonna go wash my hands". The euphemism cycle continues.

Even as words change, their definitions can still be straightforward. But definitions don't always work so easily. For example, the same sequence of sounds can have multiple meanings, like "bank," which can be the side of a river or a place where people store money.

This is known as polysemy. And it only gets trickier from there. Let’s see what the Thought Bubble is serving up.

Let’s picture the sandwich we would choose if we were going to draw an unremarkable, sandwich-y sandwich. We might consider the type of bread -- white? Whole wheat?

Square loaf or something more rustic? And we’ll probably imagine a filling. Maybe you went with a PB&J, or something with meat, cheese, and lettuce like in the emoji sandwich.

I went for a grilled cheese myself. Now let's take the sandwiches we pictured and try to write a definition for "sandwich." Maybe it's "a filling between two pieces of bread?" Or wait, a sandwich can be served on a roll, and wraps and pitas are on a lot of sandwich menus, so maybe a sandwich is "a filling between two...somewhat bread-like pieces?" A burger works. It’s got a filling between two halves of a roll.

But what about an ice cream sandwich? It’s got a filling between two cookies, and it even has sandwich in the name. And if we’re going to count wraps and rolls, does that make a burrito a sandwich?

A hot dog? A pizza? What if we fold the pizza?

And this doesn't even get into how sandwiches are different cross-culturally. Maybe your sandwich involves Vegemite or liver paste, or the Norwegian matpakke. Okay, so our sandwich definition isn't really working that well, and we probably need to figure out definitions for "filling" and…"somewhat bread-like pieces." Oh no.

We are, to use a sandwich figure of speech, in a bit of a pickle. Thanks Thought Bubble, now I want a sandwich. Or maybe...seventeen sandwiches of different definitions.

Anyway, any definition, if we think about it hard enough, starts to break down with exceptions and edge cases. How do we know whether something is a cup? Whether a dress is blue and black, or white and gold?

And that's not even getting into social constructs like genders and emotions. Maybe nothing means anything, ever! And yet, somehow, we do manage to go through the world and communicate with each other reasonably well, most of the time.

If I ask you to think of a sandwich, or a chair, or a bird, you do think of something. So maybe the problem isn't with words, it's with trying to use definitions to express their meaning. Psychology professor Eleanor Rosch came up with a different idea.

Rather than imagining we have dictionary-style, clear-cut definitions of things in our brain,. Rosch argued that instead we have prototypes or exemplars, the most typical representatives of a category. Then we can also have other category members that are more or less central depending on how similar they are to the exemplar.

For example, an exemplar of a chair probably has four legs, a rigid back, and seats one human, but that doesn't mean that a chair can't have three legs, or be extra tall, or be an adjustable desk chair. And most people's exemplars of a bird are small, feathery ones like sparrows or robins, but that doesn't mean that less-central category members like emus or penguins aren’t still birds. Rosch’s prototype theory offers us an escape hatch from definitions.

We don't need to pin down an exact set of criteria for sandwich-hood or chair-ness. Instead, we can recognize that some examples are really obvious, prototypical members of their category, and other examples are more loosely related. Both kinds of meaning are totally okay.

Delicious, even. Prototype theory works well with content words, words with meanings that we could point to, describe, or draw a picture of. It even works okay when the ideas are abstract, like happiness and democracy.

But not every word has a prototype. Take words like "the", "of", "is", "or", "if", and "every.” It doesn't make much sense to ask what a “the” looks like, or to try to think of the most prototypical example of an "of". These little words that help a sentence fit together grammatically are called function words.

They can only really be described based on their relationship to the words they're used with — their function in the sentence. To pin down exactly what these functions are, we can express the relationships between words in mathematical, symbolic terms, using predicate calculus. This concept also comes up in mathematics, computer science, or philosophy, where it can also go by the names first-order logic, quantificational logic, and first-order predicate calculus.

Predicate calculus is a branch of formal semantics — that's formal as in "using formulas", not as in the semantics you do while wearing a ballgown. At the heart of formal semantics is one assumption: to understand what a sentence means, we have to know when that sentence is true or not. And predicate calculus helps us find the meanings of certain words in those true sentences.

To see how predicate calculus works for two function words, "all" and "a", let’s start with the sentence: “All Crash Course hosts like Gav.” If it’s true, we can infer that Gav exists, and that, since I’m a Crash Course host, I like Gav. We can’t infer how many Crash Course hosts there are, but we know this sentence applies to all of them, so "all" is known as a universal quantifier. If the sentence was “A Crash Course host likes Gav,” then we could infer that there’s a Gav, and that there is one of the set of Crash Course hosts that likes them.

It might be me, but we can’t be certain! We don’t know which Crash Course host it is, only that they exist, so "a" is known as an existential quantifier. In the sentence “All Crash Course hosts like a rabbit,” we now have one universal quantifier and one existential quantifier.

This sentence actually has two different meanings:.

One: There is a rabbit that all Crash Course hosts like. Or

Two: Every Crash Course host each likes a different rabbit. It would be hard to write down this kind of meaning in a definition, let alone describe this interaction between "all" and "a” in a few words. But using symbols lets us see these relationships more clearly, and lets us see when similar functional meanings are expressed in different languages. We've only explored two function words here.

There's an extensive set of notation we can use to explore other function words, and some are still being figured out! That said, like prototype theory, predicate calculus also doesn't work for everything .These methods are just two ways to do semantics. Other approaches to semantics specialize in still more kinds of meanings, such as Binary Feature Analysis, which is useful for precisely describing words that are part of a taxonomy, like words for family members.

There's Natural Semantic Metalanguage, where words can be broken down into other, more basic units of meaning, and Cognitive Semantics, where metaphors draw connections between abstract concepts like time and concrete concepts like physical location. Some aspects of semantics highlight similarities between different, unrelated languages; other aspects highlight meanings that are more specific to a particular language or language family. There's so much more to talk about, and we would love to get into it, but we don't have time!

Trying to articulate the meaning of a word in a dictionary is an amazing skill, but meaning is complicated and nebulous and requires a range of semantic tools to pin down. Next time on Crash Course Linguistics, we'll zoom out further and talk about meaning beyond words, in a larger social context. Thanks for watching this episode of Crash Course Linguistics.

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