A dictionary is a list of words with their definitions, a list of characters with its glyph or a list of words with corresponding words in other languages. Many dictionaries also provide pronunciation information, word derivations, histories, or etymologies, illustrations, usage guidance, and examples in sentences.
Dictionaries of alphabetic languages list words in alphabetical order. With non-alphabetic languages, it may be different. The order in a dictionary with ideographic entries such as Chinese character is often troublesome and controversial because each character has different readings. Collation systems for logographs do exist. Japanese is a special case, as most words can be either "spelled" in hiragana or written in kanji, Chinese characters used in Japanese language.
There are different types of dictionaries, some are bilingual, cross references between different languages, or historical dictionaries. In those, each entry has translations words in other language. For example, in Japanese-English dictionary, an entry tsuki has a corresponding English word, moon or luna.
In East-Asisan languages, a dictionary specialized in characters has developed. Those are called Kan-wa jiten (lit Han-Japanese dictionary) in Japanese. Each entry has one Chinese character with the description about strokes, reading and a list of words using that character.
Another variant is the glossary, an alphabetical list of defined terms in a specialized field, such as medicine or science. The simplest dictionary, a defining dictionary, provides a core glossary of the simplest meanings of the simplest concepts. From these, other concepts can be explained and defined, in particular for those who are first learning a language. In English the commercial defining dictionaries typically include only one or two meanings of under 2000 words. With these, the rest of English, and even the 4000 most common English idioms and metaphors, can be defined.
Dictionaries come in two basic philosophies, prescriptive and descriptive. The Oxford English Dictionary (OED) is descriptive, and attempts to describe actual usage. Noah Webster, on the other hand, who was intent on forging a distinct identity for the American language changed the meanings and pronunciation of numerous words.
Most modern dictionaries are descriptive, although many, such as the American Heritage dictionaries make extensive efforts to provide information on the best usage, and almost all dictionaries provide some information on words considered erroneous, vulgar, or easily confused. In any case, in the long run, usage alone determines the meaning of words, although dictionaries provide conservative continuity, even the most descriptive.
Since words and their meanings develop over time, dictionary entries are organized to reflect these changes. Dictionaries may either list meanings in the historical order in which they appeared, or may list meanings in order of popularity and most common use.
Dictionaries also differ in the degree to which they are encyclopedic, providing considerable background information, illustrations, and the like, or linguistic, concentrating on etymology, nuances of meaning, and quotations demonstrating usage.
The art and craft of writing dictionaries is called lexicography. The first large English dictionary was Thomas Blount's of 1656. This was followed by Samuel Johnson's famous and more comprehensive dictionary of 1755.
Noah Webster's dictionary was published by the G&C Merriam Company of Springfield, Massachusetts which still publishes Merriam-Webster dictionaries, but the term Webster's is considered generic and can be used by any dictionary.
Major dictionaries:
Publishers:
See also: Thesaurus, Monolingual learners' dictionaries, COBUILD
The DICT protocol is a client/server model for dictionaries. Many free dictionaries are appearing in the dict format.
A dictionary project not unlike Glasgledius is the GNU Collaborative International Dictionary of English (GCIDE). This dictionary uses Webster's Revised Unabridged Dictionary (1913) and WordNet as its sources and is being developed collaboratively under the terms of the GNU General Public License. It describes itself as "a freely-available set of ASCII files containing the marked-up text of a substantial English dictionary".
Other collaborative dictionary projects: