fireboard

plural fireboards

1. A board or screen placed over a fireplace when it is not in use.

   1915, Mary E. Wilkins Freeman, Emancipation A stovepipe had been fitted into an iron fireboard covering the great fireplace

   2 more examples

   I then glanced round the room; and besides the bedstead and centre table, could see no other furniture belonging to the place, but a rude shelf, the four walls, and a papered fireboard representing a man striking a whale.

   1851 November 14, Herman Melville, “chapter 3”, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, →OCLC

   The wind whopped and spat into the chimney; and now and then a puff of wood-smoke blew out and mounted up along the blackened fireboard.

   1918, Melville Davisson Post, “chapter 2”, in Uncle Abner

   Synonyms: chimney board, hearthboard

2. AppalachiaA fireplace's mantel.
3. A piece of wood into which a fire drill is spun to create friction.