Definition of "topcoat"

He is wearing a black armband on the left sleeve of his gray topcoat.

1988, Richard E. Kim, Lost Names: Scenes from a Korean Boyhood‎, page 100

Whereas Oehler habitually wears his topcoat completely buttoned up, I leave my topcoat completely open.

2003, Thomas Bernhard, translated by Kenneth J. Northcott, Walking: Three Novellas, page 114

Then he opened his closet and took out a black topcoat. It was heavily lined with silk, soft to the touch.

2007, Ricardo Morada, So This Is the Good Old United States of America!‎, page 42

Apply two topcoats, particularly to areas that are fully exposed to the weather such as the south side of the house. A total of three coats (primer and two topcoats) should result in an optimum thickness of 4-1/2 to 5 mils.

1966, Forest Products Laboratory (U.S.), Wood Finishing: Painting Outside Wood Surfaces‎, page 2

Fig. 7 shows the microstructures of lutetium silicate topcoat on SiC/SiC composite after various exposure tests.

2007, N. Nakayama, K. Morishita, S. Ochiai, T. Sekigawa, K. Aoyama, A. Ikawa, “Evaluation of Environmental Barrier Coatings for SiC/SiC Composites”, in Dongming Zhu, Uwe Schulz, editors, Advanced Ceramic Coatings and Interfaces, page 169

Without the protection of the topcoat, your wood constantly expands and contracts and is more susceptible to warping and cracking. Topcoats also improve the look of the wood by adding depth and color.

2011, Jeff Strong, Woodworking For Dummies, unnumbered page