n. pl. dom·i·noes or dom·i·nos
- A small rectangular wood or plastic block, the face of which is divided into halves, each half being blank or marked by dots resembling those on dice.
- dominoes or dominos (used with a sing. or pl. verb) A game played with a set of these small blocks, generally 28 in number.
- A country expected to react politically to events as predicted by the domino theory: “The dominos did indeed fall in Indochina” (Arthur M. Schlesinger, Jr.).