Translations are available to and from English to Spanish, German, French, Japanese, Dutch, Swedish, Portuguese, Russian, Hungarian, and Welsh. Preference in selection has been given to free online dictionaries of high quality, useful to specialists and translators. However, downloadable and subscription material are listed if exceptionally rare, unusually well-executed. Comprehensive, covering dozens of languages. English nouns, verbs, adjectives and adverbs are organized into synonym sets, each representing one underlying lexical concept.
Different relations link the synonym sets.
You can search for synonyms, antonyms, hyponyms, troponyms, familiarity, and other relationships. Requires a Java-enabled browser. This is a combination dictionary and thesaurus that allows you to search for exact or approximate words. It also has definitions for some phrases. The searching strategy and interface can be a little confusing, but there are instructions available off the first page of the site.