Artha

Artha is a handy thesaurus based on WordNet with distinct features like global hotkey look-up, passive desktop notifications, regular expression based search, etc..

Free Open Source Windows Linux

Power Thesaurus

Power Thesaurus is a fast, comprehensive and easy-to-follow online thesaurus for writers, journalists, students and teachers.

Free Android iPhone iPad Web

WordNet

WordNet® is a large lexical database of English. Nouns, verbs, adjectives and adverbs are grouped into sets of cognitive synonyms (synsets), each expressing a distinct concept.

Free Open Source Windows Linux Web

VerbAce

VerbAce-Pro is an easy-to-use Desktop Translation Software. Translate in a mouse click From any application Access Wikipedia Quick translation option by moving the cursor

Freemium Windows Android

TemaTres

The open source way to manage formal representations of knowledge: Ontologies, Taxonomies, Thesauri, list of values.

Free Open Source Self-Hosted

TopWordsLike.com

The Top Words Like website is a great resource for finding synonyms for any given word. More information such as examples and definitions are displayed.

Free Windows Web