1. running beneath or below something
2. examining or inspecting something by running along underneath it
Usage: nautical

1. the act of running beneath or below something

Examples

• The cable was underrunning the bridge structure.
• The maintenance crew was underrunning the pipeline to check for leaks.
• The ship’s crew began underrunning the anchor chain.
• Water was underrunning the foundation of the building.
• The underrunning of the electrical lines required careful coordination.