Plain English Meaning
Landing on a runway when the wind is pushing the airplane sideways. The pilot has to fly the airplane in a slightly tilted or angled way so it stays lined up with the runway and doesn't drift off to one side as it touches down.
Full Definition
A landing made when the wind is blowing across the runway rather than straight down it, requiring the pilot to use control inputs (typically a sideslip or a crab corrected to a sideslip at touchdown) to keep the airplane aligned with the runway centerline and to prevent sideways drift during the approach, flare, and rollout.
Context Anchor
Used during approach and landing when wind direction is not lined up with the .