a conical, unlighted buoy used as a channel marker, especially on the starboard side of a channel entering from seaward.
Compare can buoy.
Origin of nun buoy
1695–1705; obsolete nun spinning top + buoy
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for nun buoy
Historical Examples of nun buoy
The boat shaved a nun-buoy outside Barmouth Point so closely that Staff could almost have touched it by stretching out his arm.The Bandbox
Louis Joseph Vance
Word Origin for nun buoy
C18: from obsolete nun a child's spinning top + buoy
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012