1. Large accumulations of congealed fat, grease, and non-biodegradable waste (such as wet wipes and plastic) that form blockages in sewage systems and water pipes.
Usage: plural form; informal; environmental/infrastructure context

Examples

• City workers discovered a massive fatberg clogging the main sewer line beneath downtown.
• Fatbergs form when people pour cooking grease down drains instead of disposing of it properly.
• The municipality launched a campaign to educate residents about the dangers of fatbergs.
• Removing fatbergs from sewage systems is costly and time-consuming for water utilities.
• Wet wipes and other non-flushable items contribute significantly to fatberg formation.
• London's water authority has battled several enormous fatbergs in recent years.