WordNet - WordNet® is a large lexical database of English.
Crowdin - Localize your product in a seamless way
WordWeb - One-click lookup in any almost any Windows program; Hundreds of thousands of definitions and synonyms; The latest international English words; Works offline, or reference to Wikipedia and web references.
TheSage - TheSage is a powerful language reference system that couples a professional dictionary of the...
Artha - Artha is a handy thesaurus based on WordNet with distinct features like global hotkey look-up...
Lingoes - Lingoes is an easy and intuitive dictionary and text translation software.