noun . 1. a coat or jacket worn under another.
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Down hairs, also called the ground hairs, are the very fine, fluffy hairs closest to the skin on some mammals. The hairs are short and crimped, which makes them highly efficient ...
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A dog 's coat is its fur. A dog can be double coated ?that is, having both a soft undercoat and a coarser topcoat. Some dog breeds are single-coated ?having only one type of ...
http://en.wikipedia.org/wiki/Coat_%28dog%29

1. A coat worn beneath another coat. 2. A covering of short hairs lying underneath the longer outer hairs of an animal's coat.
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noun. Obsolete a coat worn under another; an under layer of short hair in an animal's coat; a coating as of tarlike material applied to the exposed underside of a motor vehicle to ...
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