The third edition from 1995. Contains 35,000 synonyms. Roget's Thesaurus - Roget's Thesaurus of English words and phrases. Two, which is derived from the version of Roget's Thesaurus published in 1911. English nouns, verbs, adjectives and adverbs are organized into synonym sets, each representing one underlying lexical concept.
Different relations link the synonym sets.
The Astronomy Thesaurus - Astronomical terms. Searches may be performed in English, French, German, Italian, and Spanish. CAS General Subject Vocabulary Helper - Extensive listings for chemistry. Produced by Chemical Abstracts Service, a division of the American Chemical Society. Eurodic Autom - European Union terminology.