WordNet

WordNet is a lexical database of semantic relations between words that links words into semantic relations including synonyms, hyponyms, and meronyms. The synonyms are grouped into synsets with short definitions and usage examples. It can thus be seen as a combination and extension of a dictionary and thesaurus. While it is accessible to human users via a web browser,[2] its primary use is in automatic text analysis (natural language processing) and artificial intelligence applications. It was first created in the English language[3] and the English WordNet database and software tools have been released under a BSD style license and are freely available for download from that WordNet website. There are now WordNets in more than 200 languages. https://en.wikipedia.org/wiki/WordNet

WordNet in Action: Enhancing NLP Capabilities Through NLTK