Definition of birr

• v. i. - To make, or move with, a whirring noise, as of wheels in motion.
• n. - A whirring sound, as of a spinning wheel.
• n. - A rush or impetus; force.
• v. i. - To make, or move with, a whirring noise, as of wheels in motion.
• n. - A whirring sound, as of a spinning wheel.
• n. - A rush or impetus; force.