from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The board that receives the ends of the steps in a staircase.
from the GNU version of the Collaborative International Dictionary of English
- n. The board which receives the ends of the steps in a staircase.
from The Century Dictionary and Cyclopedia
- n. In carpentry, same as bridge-board.
notch + board (Wiktionary)