浮在表面的
Supernatant \Su`per*na"tant\, a. [L. supernatanus, p. pr. of supernatare to swim above; super above + natare to swim.] Swimming above; floating on the surface; as, oil supernatant on water.
supernatant adj : of a liquid; floating on the surface above a sediment or precipitate; "the supernatant fat was skimmed off" n : a liquid lying above a sediment (floating on the surface)