tegmen
noun
teg·men ˈteg-mən 
plural tegmina ˈteg-mə-nə
: a superficial layer or covering usually of a plant or animal part
Word History
Etymology
New Latin tegmin-, tegmen, from Latin, covering, from tegere to cover — more at thatch
First Known Use
1807, in the meaning defined above
Medical Definition
tegmen
noun
teg·men ˈteg-mən
plural tegmina -mə-nə
: an anatomical layer or cover
specifically : tegmen tympani