- 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. Synsets are interlinked by means of conceptual-semantic and lexical relations. The resulting network of meaningfully related words and concepts can be navigated with the browser. WordNet is also freely and publicly available for download.
- Urban Dictionary (UD). UD is a popular online slang dictionary with definitions written and voted on by users.
- Natural Language Processing - (Opinion mining | Sentiment (Analyze|classification)) - Emotion: Opinion Mining, Sentiment Analysis, and Opinion Spam Detection with an Opinion Lexicon (or Sentiment Lexicon). A list of positive and negative opinion words or sentiment words for English.
- The Harvard General Inquirer is a lexicon attaching syntactic, semantic, and pragmatic information to part-of-speech tagged words.