Source : Webster's Revised Unabridged Dictionary (1913)

Birr \Birr\, v. i. [imp. & p. p. {Birred}; p. pr. & vb. n.
   {Birring}.] [Cf. OE. bur, bir, wind, storm wind, fr. Icel.
   byrr wind. Perh. imitative.]
   To make, or move with, a whirring noise, as of wheels in
   motion.