セレニウムせれにうむMeanings1nounseleniumChemical element with symbol Se and atomic number 34. Often referred to by the synonym セレン in Japanese.See also: セレンセレニウムは人じん体たいに必ひつ要ような微び量りょう元げん素その一ひとつです。Selenium is one of the trace elements essential for the human body.