the.com/pane

Glass that's doing its best impression of not being there.

means A single sheet of glass set into a window or door frame.

from From Old French 'pan', meaning a piece or section of something (like a panel of cloth or a section of a wall), which traces back to Latin 'pannus' — a piece of cloth or rag. The word drifted from general 'section' to specifically the glass-filled section of a window as multi-paned windows became common.

etymology
from latin pannus, meaning cloth or rag
window panes
once taxed by count in 18th century england
tax dodge
houses built with fewer, bigger panes to save money
the.com · every word