su·per·natant I. \|süpə(r)+\adjective Etymology: Latin supernatant-, supernatans, present participle of supernatare to float, from super- + natare to swim — more at nourish : floating on the surface < the copra was boiled with water and the supernatant fat skimmed off — T.P.Hilditch > II. noun (-s) : a supernatant substance