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.
deuterium. the mass 2 isotope of hydrogen; it is available as a gas or heavy water and has been used as a tracer or indicator in metabolic studies.euterium oxide, or heavy water, is formed from an isotope of hydrogen, which has twice the weight of ordinary hydrogen (hence the name). the mass 2 isotope of hydrogen, symbol 2 H or D; it is available as a gas or heavy water and is used as a tracer or indicator in studying metabolism.