What does the word coating mean?

Usage examples for coating

  1. In numerous instances burial places were discovered where the bodies had been placed with the face up and covered with a coating of plastic clay about an inch thick. – A further contribution to the study of the mortuary customs of the North American Indians First Annual Report of the Bureau of Ethnology to the Secretary of the Smithsonian Institution, 1879-80, Government Printing Office, Washington, 1881, pages 87-204 by H. C. Yarrow
  2. When he came back from France, the day Lucile saw him sitting on the bench in the park, he found it exactly- save for a heavy coating of dust- as he had left it, in 1917, when he went down to Camp Grant. – Mary Wollaston by Henry Kitchell Webster
  3. They walked briskly up to the massive gold and black entrance, and passed through the great doors that seemed made of solid copper, painted with some clear coating that kept the metal lustrous, the rich color shining magnificently. – The Black Star Passes by John W Campbell