Lexicon

noun

All of the words that make up the language of a group of people, an individual, or an area of knowledge or practice
A book or other collection that lists words and their meanings
All of the individual morphemes and their combinations present in a language
Any complete stock or catalogue

Usage

If you ever accidentally wander into a Star Trek convention, you may be forgiven for thinking you've actually landed in another galaxy. Besides being surrounded by Romulans, Klingons and Vulcans, you are immersed in the lexicon used by legions of "trekkies" - a complex lattice of words and phrases the likes of which could only be derived by complete absorption into the world of the show. Language truly is the foundation of culture; so perhaps it makes sense that a detailed lexicon is key to banding what would otherwise be a disparate group of fans into a veritable nation of devotees!

The term lexicon is used to refer to the complete vocabulary of a language. It can describe either an abstract, generally known body of terminology or a physical collection of words and definitions, such as a print or online dictionary. Any group that has a specialized or characteristic set of vocabulary has a lexicon, whether it is a small European nation with its own language or a type of mechanical engineers who use their own jargon. Even an individual can have his or her own lexicon if they use an idiosyncratic vocabulary; for example, a scientist might invent her own set of terms to describe a previously undiscovered phenomenon she is studying.

These lists of words are especially useful in describing practices that are so nuanced or unique that they require a set of terms and meanings beyond ordinary language. For this reason, specific occupations and fields of study often have their own lexicons; if you've ever listened to a conversation about computer programming or music theory, you're probably aware of the wide variety of terms needed to describe these fields. Often, these lexicons become so detailed that the speakers can sound like they're using a foreign language!

Lexicon is often used interchangeably with the word dictionary, and in fact the two have extremely similar meanings. Both describe a complete list of words in a vocabulary, almost always in alphabetical order, and their definitions. However, a dictionary almost always includes other features such as synonyms and pronunciations, while a lexicon may or may not. Another similar word, glossary, is simply a list of words and definitions.

A slightly different usage of lexicon describes the complete set of morphemes in a language and all of the different combinations they can form. Morphemes are the smallest significant units in a language, and they are combined and rearranged to form useable words. For example, the word icecaps has three morphemes: ice, cap, and s. Morphemes are a decidedly abstract concept, and, as a result, this meaning of lexicon is used mostly in academic circles.

Finally, as useful as the term is to describe vocabulary, lexicon can also be applied in situations beyond linguistics. In general, the term sometimes refers to any complete set or registry. For example, you can easily describe the lexicon of different cooking utensils, Led Zeppelin songs, or literature of the American South. Although other terms like repertoire or collection might be more commonplace, lexicon is often used when trying to give a situation more gravitas, trying to sound more academic, or simply attempting to spice up ordinary conversation!

Example: No one could ever understand the homeless man, as he seemed to have his own lexicon of grunts and hiccups.

Example: Many enlistees have trouble learning all of the strange terms in the complex lexicon of the United States Navy.

Example: In the vast lexicon of store-bought cookies, the Grab-N-Bag generic brand has always been my favorite.

Derivative Words

Lexicology is the study of the specific meanings and uses of words. Lexicography (and its derivative forms lexicographically and lexicographical) describes the act of compiling a lexicon or dictionary, while a lexicographer is the person who does the aforementioned compiling. Finally, lexical is an adjective that describes something that is characteristic of or related to vocabulary or lexicography.

Example: Linguists interested in the field of lexicology must familiarize themselves with the concept of morphemes.

Example: Since languages are always evolving, the work of a lexicographer is never done!

Example: When Sarah was ten, her lexical interests led her to check out a dictionary from her elementary school library and attempt to read it cover to cover.

Origin

Lexicon is Greek in origin, formed from the terms lexikos, which means "related to words," and lexikon, which translates to "word book." The word took on its familiar spelling as it made its way into Latin, and would be eventually used to describe Greek, Arabic, and Hebrew dictionaries written in that language. Lexicon entered the English lexicon in the seventeenth century. (Writing that last sentence tickles this lexicographer on a lexical level)

In Literature

From John Nichols' The Nirvana Blues: a Novel:

For what could be worse, in the great lexicon of all lexicons, than mugging an angel as if it were some common atheisn'c thug?

Here, lexicon is used in perhaps the most general sense possible, as it refers to all of the possible actions that can possibly be committed.

Similar Words

Lexis is a word which also describes a complete list of the words used in a language. Although lexis and lexicon are similar in meaning and appearance, they are entirely separate words. Both share the same roots; however, they should not be confused as derivatives or alternate forms of one another.

Mnemonic

You can look up any word if you've got it on your lexicon!
Go to Comic Con, learn funny lexicon.