Searchlight (noun)

A powerful light that is used for illuminating a large area, especially at night.

Origin:

19th century: search + light.

Examples:

1. The searchlight scanned the night sky, looking for enemy aircraft.
2. The searchlight was used to guide ships into port.
3. The searchlight was mounted on a police helicopter, helping to find suspects on the ground.
4. The searchlight was used by the army to search for enemy troops in the darkness.
5. The searchlight was part of a lighthouse, warning ships of rocks and shoals.