The term 'They Died With Their Boots On, For One' can be summarized as referring to a classic western movie. The crossword solution for this term is 'OATER', which is an abbreviation for 'OATER', a slang term for a western movie. Oaters were popular in the early days of film and often featured cowboys, horses, and gunfights. They Died With Their Boots On is a 1941 western starring Errol Flynn and Olivia de Havilland, and is considered one of the best examples of the genre.