The Collaborative International Dictionary
Underbear
Underbear \Un`der*bear"\, v. t. [AS. underberan. See Under, and Bear to support.]
To support; to endure. [Obs.]
--Shak.To line; to guard; to face; as, cloth of gold underborne with blue tinsel. [Obs.]
--Shak.
Wiktionary
underbear
vb. 1 To support, endure. 2 (context transitive English) To line, guard or face a material, especially cloth.