Lex Luthor is a supervillain in the DC Comics universe. He is one of Superman's most notorious enemies and is known for his genius-level intellect and wealth. Lex Luthor is often depicted as a power-hungry megalomaniac, using his vast resources to achieve his goals. He has been featured in various media adaptations, including television series, films, and video games. The three letter crossword solution for Lex Luthor is 'LEX'.