fogsignal
/ˈfɑɡˌsɪɡnəl/
noun
- A warning signal, such as a horn, bell, or light, used by ships or lighthouses to alert vessels in foggy conditions.
- The lighthouse's fogsignal boomed every thirty seconds during the storm.
- We heard the eerie sound of a fogsignal echoing across the harbor.
- Sailors rely on the fogsignal to avoid crashing into rocks when visibility is low.