Plain English Meaning
The aircraft is too high for the planned descent toward the runway. The visual approach lights are telling the pilot to come down to get back on the correct path.
Full Definition
A position during a visual approach in which the aircraft is higher than the published or indicated descent path to the runway threshold. On a standard two-bar VASI, this condition is shown when both light bars appear white.
Context Anchor
Seen on final approach, especially when using a visual approach slope indicator () beside the runway.