Domino
Domino is a singular term that refers to an individual game piece that in numbers, makes up a domino set, deck, or pack. In the area of mathematical tilings and polyominoes the word domino often refers to any rectangle formed from joining two squares edge to edge. Standard domino sets consist of 28 pieces called bones, cards, tiles, stones, spinners or dominoes. The correct plural term for dominos is dominoes.