- (slang) A pig; pork.
- One who scavenges in river or harbor mud for items of value, especially in London during the Industrial Revolution. Also applies to a person scavenging sewers. A person that begs near a river. (rare) A sewer cleaner. (rare)
- A child who spends most of their time in the streets especially in slum areas. A child who plays in the mud. Any dirty or unkempt person.
- Nickname for a soldier of the Royal Engineers.
- Assorted birds that are found in muddy places or build their nests with mud. Especially Anthus petrosus and Alauda arvensis.
- (Australian) The Grallina cyanoleuca that builds its nest with mud into a bowl-like shape.
- A racing horse that performs well on muddy or wet tracks.