underfur. / (ˈʌndəˌfɜː) / noun. the layer of dense soft fur occurring beneath the outer coarser fur in certain mammals, such as the otter and sealAlso called: undercoat.

What is the purpose of Underfur?

The guard hair keeps moisture from reaching the skin; the underfur acts as an insulating blanket that keeps the animal warm. The fur of mammals has many uses: protection, sensory purposes, waterproofing, and camouflaging, with the primary usage being thermoregulation.

What is hair undercoat?

1 : a coat or jacket worn under another. 2 : a growth of short hair or fur partly concealed by the longer and usually coarser guard hairs of a mammal.