Reverse Dictionary

A reverse dictionary is a dictionary organized in a non-standard order that provides the user with information that would be difficult to obtain from a traditionally alphabetized dictionary. For example, A Reverse Dictionary of the Spanish Language and Walker's Rhyming Dictionary are reverse dictionaries, the organization of which is based upon sorting each entry word based upon its last letter and the subsequent letters proceeding toward the beginning of that word. Consequently, in these reverse dictionaries all words that have the same suffix appear in order in the dictionary. Such a reverse dictionary would be useful for linguists and poets who might be looking for words ending with a particular suffix, or by an anthropologist or forensics specialist examining a damaged text (e.g. a stone inscription, or a burned document) that had only the final portion of a particular word preserved. Reverse dictionaries of this type have been published for most major alphabetical languages (see numerous examples listed below). By way of contrast, in a standard dictionary words are organized such that words with the same prefix appear in order, since the sorting order is starting with the first letter of the entry word and subsequent letters proceeding toward the end of that word.

Reverse dictionaries of this type were historically difficult to produce before the advent of the electronic computer and have become more common since the first computer sorted one (Stahl and Scavnicky's Reverse Spanish Dictionary) appeared in 1974.

Another use of the term "reverse dictionary" is for a reference work that is organized by concepts, phrases, or the definitions of words. This is in contrast to a standard dictionary, in which words are indexed by the headwords, but similar in function to a thesaurus, where one can look up a concept by some common, general word, and then find a list of near-synonyms of that word. (For example, in a thesaurus one could look up "doctor" and be presented with such words as healer, physician, surgeon, M.D., medical man, medicine man, academician, professor, scholar, sage, master, expert.) In theory, a reverse dictionary might go further than this, allowing you to find a word by its definition only (for example, to find the word "doctor" knowing only that he is a "person who cures disease"). Such dictionaries have become more practical with the advent of computerized information-storage and retrieval systems (i.e. computer databases).

An example of this type of reverse dictionary is the Diccionario Ideológico de la Lengua Española (Spanish Language Ideological Dictionary) This allows the user to find words based on a small set of general concepts.