Definition of "locknut" []

• A usually thin nut screwed down on another nut to prevent it from loosening. (noun)
• A self-locking nut. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Also Clay, that locknut is used to, I was told set the head spacing for the rifle."
• "I call it the “syncopated pedaling creak,” usually a sign that the locknut on a campy cassette is not tight enough."
• "The locknut (if fitted) has to be released to allow the operating screw to move and should be relocked after each adjustment."