1. Milled, as the head of a screw, or the edge of a coin 
2. Full of knots; gnarled

1. To provide with ridges, to assist the grasp, as in the edge of a flat knob, or coin; to mill

Encyclopedia: Knurl

• ball and chain
• ball bearing
• ball boy
• ball carrier
• ball cartridge
• ball club
• ball fern
• ball field
• ball gown
• ball hawk
• ball lightning
• ball nettle
• ball nightshade
• ball of fire
• ball over
• ball valve
• ball-and-socket joint
• ball-breaker
• ball-buster
• ball-hawking
• ball-peen hammer
• ball-shaped
• ballad
• ballad maker
• ballade