Lex is a term with multiple meanings depending on context:
1. In linguistics, lex is short for "lexicon", referring to the vocabulary of a language or a person.
2. In computing, LEX is a program generator for lexical analysis of character input streams.
3. As a name, Lex is often a short form of Alexander or Alexis.
4. In popular culture, Lex Luthor is the archenemy of Superman in DC Comics.
5. Lex Fridman is a well-known AI researcher and podcast host.