Flat section of a wall (5)

I believe the answer is:

panel

(Other definitions for panel that I've seen before include "Plane (anag.)" , "Group of experts etc" , "Piece of wood" , "Judging committee" , "Wall mounting" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.