1. Sludge (rich in organic matter) that accumulates at the bottom of lakes or oceans
   "Scientists studied the sapropel to understand ancient climate conditions"

Derived forms: sapropels

Type of: gloop [Brit, Cdn, informal], goo [informal], gook [informal], goop [N. Amer, informal], guck [N. Amer, informal], gunk [informal], muck, ooze, slime, sludge

Encyclopedia: Sapropel