fatberg
/ˈfatbəːɡ/noun chiefly British
A very large mass of solid waste in a sewerage system, consisting especially of congealed fat and personal hygiene products that have been flushed down toilets: repairs on 20 metres of damaged pipe affected by the fatberg started on Monday...
- Nevin, of the water service, said the fatberg was a build-up of inappropriate materials put into the sewer network.
- The fatberg underneath Oxford is not the first of its kind.
- The fatberg was removed by workmen using high-pressure water jets.
Origin
Early 21st century: from fat and iceberg.