sheepskin

Short definition from Wiktionary

Noun

1. 1
   The skin of a sheep, especially an adult sheep, and especially when used to make parchment or in bookbinding.
2. 2
   The skin of a sheep, especially an adult sheep, and especially when used to make parchment or in bookbinding: The tanned skin of a sheep with the fleece left on, especially when used for clothing, rugs, etc.
3. 3
   A diploma, especially the one representing a university or college degree.