ˈflash-board
[f. flash v.1 + board n.]
a. (See quot. 1768.) b. A board set up on edge upon a mill-dam, when the water is low, to throw a larger quantity of water into the mill-race.
| 1768–74 Tucker Lt. Nat. (1852) I. 32 The miller of an overshot mill..has shoots lying over every one of his wheels, stopped by flash-boards, at their upper ends. Ibid. Should an eel wriggle under any of the flash-boards, this might give the water a passage without any act of the miller. 1860 Bartlett Dict. Amer., Flash Board. 1868 Peard Water-Farm. xv. 158 When..the connecting canals have been cut, and the flash-boards erected. |
| fig. 1822 T. L. Peacock Maid Marian iv, He pulled up all the flash-boards at once and gave loose to the full torrent of his indignation. |