A warning signal is a sound or visual cue that alerts people to potential danger. TOCSIN (6 letters) is an old-fashioned term for a warning bell, ALERT (5 letters) is a signal of danger or caution, BEACON (6 letters) is a light or other signal used to warn or guide, SIREN (5 letters) is a loud noise used to ALERT people to danger, ALARM (5 letters) is a device that makes a loud noise when triggered, BEEP (4 letters) is a short, high-pitched sound, HORN (4 letters) is a loud noise made by a vehicle, KLAXON (6 letters) is a loud HORN used as a warning signal, Redflag (7 letters) is a sign of danger or warning, and Alarmbell (9 letters) is a bell that rings to ALERT people to danger.