- The definition of hairbrained, another spelling for harebrained, is silly, ill-considered or unlikely to be effective.
A crazy scheme that you come up with that doesn't make much sense is an example of a hairbrained scheme.
hairbrained definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
Origin: by folk etymology after hair
hairbrained definition by American Heritage Dictionary
adjective Usage Problem
Harebrained. See Usage Note at harebrained.
Origin: Variant of harebrained.