重じゅう水すいじゅうすいMeanings1nounheavy waterScientific term for water containing a higher proportion of deuterium oxide (D₂O). Used in nuclear reactors and research.重じゅう水すいは原げん子し炉ろで中ちゅう性せい子しの減げん速そく材ざいとして使つかわれる。Heavy water is used as a neutron moderator in nuclear reactors.