WordNet
Software / App
Lexical knowledge base referenced as a resource in lexical nets/chains (used in NLP for semantic relations).
Mentioned in 3 videos
Videos Mentioning WordNet

Key Phrase Indexing With Controlled Vocabularies
GoogleTalksArchive
Lexical knowledge base referenced as a resource in lexical nets/chains (used in NLP for semantic relations).

David Ferrucci: IBM Watson, Jeopardy & Deep Conversations with AI | Lex Fridman Podcast #44
Lex Fridman
A lexical database for English, used by Watson as a semantic resource.

David Ferrucci: The Story of IBM Watson Winning in Jeopardy | AI Podcast Clips
Lex Fridman
A large lexical database of English, used by Watson as a semantic resource.