Other forms: panels
A panel is a flat section set into a door or a wall. Framed, slightly recessed, and often carved.
Building and joinery use it constantly, and panelling is a wall lined with wooden panels. Cars have body panels and machines have control panels. The completely separate sense is a group of people chosen to judge or discuss something, which is where a panel of experts, a panel game and a jury panel all come from. Both senses come from the same old word for a small piece, and a solar panel is the modern flat one.
A panel was a piece of cloth. Latin pannus meant cloth or rag, and its diminutive gave Middle English a word covering a saddle pad, a pane of glass and a jury list all at once, which is where a panel of experts comes from.
Proto-Indo-European
*peh₂n- — fabric
Latin
pannus — cloth, rag, garment
Vulgar Latin
*pannellus
Anglo-Norman
panel
Middle English
panel — piece of cloth, saddle pad, pane of glass, piece of ice, part, division, jury list, jury members
English, today
panel
Built from
From Middle English panel (“piece of cloth, saddle pad, pane of glass, piece of ice, part, division, jury list, jury members”), from Anglo-Norman panel, panelle (“piece of cloth, saddle cushion”), from Vulgar Latin pannellus, diminutive of Latin pannus (“cloth, rag, garment”), from Proto-Indo-European peh₂n- (“fabric”). Cognate with Old English fana (“a piece of cloth, patch, banner, flag, vane”). a doublet of vane.
Etymology from Wiktionary, CC BY-SA