The term BASE COAT refers to a type of paint that is applied to a surface before the topcoat. The two crossword solutions for this term are SEALER (6 letters) and PRIMER (6 letters). A SEALER is a type of paint or coating that is used to protect the surface from moisture, dirt, and other contaminants. A PRIMER is a type of paint that is used to prepare a surface for painting and to help the paint adhere better. Both sealers and primers are important components of the base coat.