sed ‧ i ‧ ment /ˈsedəmənt, ˈsedɪmənt/ BrE AmE noun [uncountable and countable]
[ Date: 1500-1600 ; Language: Latin ; Origin: sedimentum , from sedere 'to sit, sink down' ]
solid substances that settle at the bottom of a liquid:
a thick layer of sediment