noun. A mixture of butter and suger. A mixture of butter and suger. The definition of a mixture is a combination of different things, or the state or act of being mixed. 1  An example of a mixture is a bowl of butter, sugar and salt. 2  An example of mixture is the process of combining flour and baking soda.
deuterium oxide. An isotope of water in which hydrogen has been displaced by its isotope deuterium. Its properties differ from ordinary water in that it has higher freezing and boiling points and is incapable of supporting life.
Deuteron. The nucleus of the atom of heavy hydrogen, 2 H (deuterium). The deuteron d is composed of a proton and a neutron; it is the simplest multinucleon nucleus. Its binding energy is 2.227 MeV; that is, this is the amount of energy which must be added to a deuteron for it to dissociate into a proton and a neutron.