ArtLex [ Teens/Mature Teens ] - Dictionary of visual art defines more than 3,500 art-related terms. Also includes a comprehensive collection of artwork and famous quotes. http://www.artlex.com/

Biographical Dictionary [ Kids/Teens/Mature Teens ] - Read about more than 28,000 notable men and women from history. Search by names, dates, professions, achievements, and more. http://s9.com/

Dictionary.com [ Kids/Teens/Mature Teens ] - Online English dictionary, thesaurus and reference guide. Includes word games, online translator, and word of the day feature. http://dictionary.reference.com/

DinoDictionary.com [ Kids/Teens/Mature Teens ] - Features profiles of over 300 known dinosaurs along with pronunciations of their names. http://www.dinodictionary.com/

eLook Dictionary [ Kids/Teens ] - Provides definitions, synonyms, and related words. http://www.elook.org/dictionary/

Fact Monster [ Teens/Mature Teens ] - An online dictionary with definitions of more than 125,000 words. http://www.factmonster.com/dictionary.html

Free On-line Dictionary of Computing [ Kids/Teens/Mature Teens ] - A searchable dictionary of terms from computing and related fields. http://foldoc.doc.ic.ac.uk/foldoc/index.html

Giant Picture Dictionary [ Kids/Teens ] - Free online picture dictionary. Includes pictures representing both concrete and abstract concepts. http://www.giantpicturedictionary.com/

Ice Phoenix Vocab Project [ Teens/Mature Teens ] - Downloadable program that looks up entire lists of vocabulary words. http://iphoenix.sourceforge.net/

InfoVisual Thematic visual dictionary by Bernard D?ry, to learn by way of image. Concise definitions within the fields of vegetal biology, animal biology, and human anatomy. http://www.infovisual.info/

Little Explorers [ Kids ] - Picture dictionary gives definitions, pictures, and Internet links for over 2,350 entries. Includes translations for English to and from Dutch, French, Spanish, and more. http://www.EnchantedLearning.com/Dictionary.html

MSN Encarta Dictionary [ Kids/Teens/Mature Teens ] - Online dictionary with over 100,000 entries, definitions, and pronunciations. http://encarta.msn.com/encnet/features/dictionary/dictionaryhome.aspx

NetLingo Dictionary [ Teens/Mature Teens ] - Provides a glossary of Internet jargon and acronyms. http://www.netlingo.com/

OneLook Dictionary Search [ Kids/Teens/Mature Teens ] - Type in a word and search many dictionaries at once. Also has a reverse dictionary. http://www.onelook.com/

PSEUDOdictionary [ Teens/Mature Teens ] - Defines everyday words including slang, webspeak, and colloquialisms. http://www.pseudodictionary.com/

Realdictionary.com [ Kids/Teens/Mature Teens ] - Features search to locate words by initial letters and numbers. http://www.realdictionary.com

RhymeZone [ Kids/Teens/Mature Teens ] - Online rhyming dictionary. Search for a word and get a list of potential words that rhyme in addition to a definition. http://www.rhymezone.com/

Tech Terms Computer Dictionary [ Mature Teens ] - A searchable dictionary of computer terms with definitions explained in simple language. http://www.techterms.org

Terminology Collection: Online Dictionaries [ Teens/Mature Teens ] - Glossaries for several languages and for specialized fields from the University of Vaasa, Finland. http://www.uwasa.fi/comm/termino/collect/

The American Heritage Dictionary of the English Language [ Kids/Teens/Mature Teens ] - Contains over 90,000 entries, including 70,000 audio word pronunciations. http://www.bartleby.com/61/