A mudheap is a pile of wet, sticky earth that can often be found on building sites or in agricultural areas. Variations of this term include mud pile, mud mountain, and mudbank. Other synonyms for mudheap might include mire or sludge, both of which describe a thick and viscous type of mud. Another similar term is quagmire, which refers to a wet and boggy area of land. If you're considering other words to describe a grimy or dirty situation, you could use terms like filth, grime, or muck. However, if you're specifically looking for synonyms for mudheap, these terms should give you plenty of options.