Plain English Meaning
At night, a pilot sees a lone light on the ground and thinks it's a star in the sky. Trying to fly with that 'star' overhead, the pilot unknowingly tilts or banks the aircraft into a dangerous attitude.
Full Definition
A form of spatial disorientation in which a pilot flying at night mistakes a single ground light, or a stationary light against a dark background, for a star, causing the pilot to lose proper attitude reference and place the aircraft in an unusual attitude while trying to keep the light above the horizon.
Context Anchor
Seen in instrument-flying training when learning why pilots must trust their instruments instead of body sensations in low-visibility conditions.