The crossword solution for the term 'Nick and ___ Charles' is Nora, a four-letter word. Nick and Nora Charles are the main characters in Dashiell Hammett's novel The Thin Man, which was later adapted into a popular movie series. They are a married couple who solve mysteries together. Nick is a former private detective and Nora is a wealthy socialite. The couple is known for their witty banter and their love of martinis.