WordWeb Online

1. Hybrid offspring of a male donkey and a female horse; usually sterile
    
2. A slipper that has no fitting around the heel
   - scuff
    
3. A test vehicle fitted with prototype components
    
4. A small vehicle or locomotive
    
5. [informal] A person paid to smuggle drugs
    
6. A stubborn person

Sounds like: mucus, mucmule

Derived forms: mules

Type of: carpet slipper, equid, equine, slipper

Part of: Equus, genus Equus

Encyclopedia: Mule, Norway