ignis fatuus ( def 1 ).
anything that deludes or misleads by luring on.

1600–10; orig. Will (i.e., William) with the wisp; see wisp

willo'-the-wispish; especially British, willo'-the-wispy, adjective
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To will-o'-the-wisp
World English Dictionary
will-o'-the-wisp (ˌwɪləðəˈwɪsp)
1.  friar's lantern, ignis fatuus, Also called: jack-o'-lantern a pale flame or phosphorescence sometimes seen over marshy ground at night. It is believed to be due to the spontaneous combustion of methane or other hydrocarbons originating from decomposing organic matter
2.  a person or thing that is elusive or allures and misleads
[C17: originally Will with the wisp, from Will short for William and wisp in former sense of a twist of hay or straw burning as a torch]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

1661, earlier Will with the wisp (1608), from the masc. proper name Will + wisp "bundle of hay or straw used as a torch."
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
Encyclopedia Britannica


in meteorology, a mysterious light seen at night flickering over marshes; when approached, it advances, always out of reach. The phenomenon is also known as will-o'-the-wisp and ignis fatuus (Latin: "foolish fire"). In popular legend it is considered ominous and is often purported to be the soul of one who has been rejected by hell carrying its own hell coal on its wanderings. The phenomenon is generally believed to be due to the spontaneous ignition of marsh gas, which consists mostly of methane and which is produced by the decomposition of dead plant matter

Learn more about will-o'-the-wisp with a free trial on Britannica.com.

Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature