This online dictionary, entirely in Arabic, gives Arabic synonyms and antonyms of words entered into the dictionary, helping to expand the vocabulary of anyone using it. It also gives rhyming words for those interested in writing poetry or for any other reason one might need a rhyming word. The broken plurals of words are also displayed.
This dictionary of medical terminology was assembled by the World Health Organization in order to "to meet the urgent need in Arab countries for unified medical terms." The current edition of the dictionary contains over 150,000 terms in English and Arabic. Users can search the dictionary on this site.
Wictionary is a free dictionary that gives definitions in 170 different languages. The dictionary only gives definitions within the language, not from language to language. Intended as a lexical companion to the encyclopedia project Wikipedia, Wictionary includes etymologies, pronunciations, quotations, synonyms, and antonyms where appropriate. Users can add definitions by creating an account. Certain words for Arabic also include masdars. An audio component is included for certain languages, Arabic not among them.