Plain English Meaning

When you roll the airplane into a turn using the ailerons alone, the nose initially swings the wrong way — away from the turn — before coming around. The wing that goes up creates extra drag, which drags that side of the airplane backward.

Full Definition

The tendency of an airplane's nose to yaw in the opposite direction of a roll when the ailerons are deflected. The down-going aileron (on the rising wing) creates more lift but also more induced drag than the up-going aileron on the descending wing, pulling that wing back and yawing the nose away from the intended turn.

Context Anchor

You encounter adverse yaw during basic flight training when learning turns, roll control, and proper use.