Plain English Meaning

The part of the wind that pushes you sideways across the runway, rather than straight down it. The bigger the angle between the wind and the runway, the more of the wind ends up shoving you sideways.

Full Definition

The portion of the wind blowing perpendicular (at 90 degrees) to the runway centerline or aircraft's intended track, expressed in knots. It is calculated from the total wind speed and the angle between the wind direction and the runway heading.

Context Anchor

Used when planning takeoffs and landings, especially when comparing the wind to what the airplane and pilot can safely handle.

Derivation

Crosswind comes from cross (across) plus wind. Component is from Latin componere, meaning 'to put together' -- here it means one piece of the total wind that has been into two parts: the / portion (along the runway) and the crosswind portion (across it).