Wikipedia does not currently have an article on "crackpot", but its sister project Wiktionary does:

Read the Wiktionary entry on "crackpot"

You can also:

• Search for Crackpot (person) in Wikipedia to check for alternative titles or spellings.
• Start the Crackpot (person) article, using the Article Wizard if you wish, or add a request for it; but please remember that Wikipedia is not a dictionary.
  wiktionary:crackpot