Plain English Meaning

A grooved runway has small lines cut into its surface that give rainwater somewhere to go, so the tires can still touch the runway instead of riding on top of a layer of water.

Full Definition

Describes a runway surface into which shallow, evenly spaced channels have been cut across the pavement to allow standing water to drain off and escape from beneath the tires, improving tire-to-runway contact in wet conditions and reducing the likelihood of dynamic hydroplaning.

Context Anchor

Seen in wet-runway, landing-distance, braking, and hydroplaning discussions.

Derivation

From the Old English grof, meaning a furrow or channel cut into a surface. The aviation use is literal: shallow channels are physically cut into the pavement.