The crossword solution for the term 'Young Man with a HORN' is HORN, which is a four-letter word. The phrase 'Young Man with a HORN' is a reference to a novel by the same name written by Dorothy Baker in 1938. The novel follows the story of a young jazz musician who struggles with his own inner demons and the pressures of fame. The title of the novel is derived from a phrase in the Bible, which reads 'Blow ye the trumpet in Zion, and sound an alarm in my holy mountain: let all the inhabitants of the land tremble: for the day of the LORD cometh, for it is nigh at hand.'