Plain English Meaning

Wind blowing from behind you, in the direction you're going. It speeds you up over the ground but doesn't help your wings produce lift.

Full Definition

Winds blowing in the same direction the aircraft is traveling, pushing it from behind. A tailwind increases groundspeed (speed over the ground) but does not increase airspeed (speed of the air over the wings). On takeoff and landing, a tailwind lengthens the ground roll and is generally undesirable; in cruise, a tailwind shortens trip time and saves fuel.

Context Anchor

You will see this term in traffic pattern, runway selection, takeoff and landing, and discussions.