Metal ball bearings.Licensed from iStockPhoto
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
- a bearing in which the moving parts revolve or slide on freely rolling metal balls so that friction is reduced
- any of such metal balls
Used by arrangement with John Wiley & Sons, Inc.
noun Abbr. bbThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
- A friction-reducing bearing consisting essentially of a ring-shaped track containing freely revolving hard metal balls against which a rotating shaft or other part turns.
- A hard ball used in such a bearing.
ball bearing - Science Definition
The American Heritage® Science Dictionary
- A ring-shaped track containing hard metal balls that roll freely, used to reduce friction where a rotating element (such as an axle) is attached to a fixed point.
- A hard ball used in such a track.
Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.