1. The first or preliminary coat of paint or size applied to a surface
   "The painter applied an undercoat to the wall before adding the final colour";
   - flat coat, ground, primer, priming, primer coat, priming coat
    
2. Thick soft fur lying beneath the longer and coarser guard hair
   "The undercoat of many mammals provides excellent insulation";
   - underfur
    
3. Seal consisting of a coating of a tar or rubberlike material on the underside of a motor vehicle to retard corrosion
   "The new car came with an undercoat to protect it from rust";
   - underseal [Brit]

1. Cover with a primer; apply a primer to
   "They undercoated the walls before applying the final paint colour";
   - prime, ground

Derived forms: undercoating, undercoats, undercoated

Type of: coat of paint, fur, paint, seal

Encyclopedia: Undercoat