domino: a small rectangular block used in playing the game of dominoes; the face of each block has two equal areas that can bear 0 to 6 dots
entity: that which is perceived or known or inferred to have its own distinct existence (living or nonliving)
vx gas: a highly lethal nerve agent used in chemical warfare; a toxic liquid that penetrates the skin or lungs to disrupt the nervous system and stop respiration; in combat VX gas is deployed by detonating a container over the target area and can persist in the environment up to several weeks after release