Source : Webster's Revised Unabridged Dictionary (1913)

Boss \Boss\ (b[o^]s), v. t. [imp. & p. p. {Bossed} (b[o^]st); p.
   pr. & vb. n. {Bossing}.] [OE. bocen, fr. OF. bocier. See the
   preceding word.]
   To ornament with bosses; to stud.