The crossword solution for the term 'THEY'RE CALLING, IN 'DANNY BOY'' is 'PIPES' (5 letters). The phrase 'they're calling' is a reference to the traditional Irish folk song 'Danny Boy', which is often played on the bagpipes. The song is about a man who is leaving his home and is saying goodbye to his loved ones. The phrase 'they're calling' refers to the sound of the pipes, which is used to signify the man's departure.