The majority of the etymologies on this site have been drawn from a core collection of reference sources. At the bottom of each word/phrase entry, you'll see a list of several numbers, each corresponding to a particular book, dictionary or encyclopedia used when researching that particular entry. These core sources are numbered (in no particular order) as follows:
1. Simpson, John, and Edmund Weiner, eds. The Oxford English Dictionary, 2nd ed. New York: Oxford University Press, 1989.
2. Dalzell, Tom, ed. The Routledge Dictionary of Modern American Slang and Unconventional English. New York: Routledge, 2008.
3. Hendrickson, Robert. QPB Encyclopedia of Word and Phrase Origins. New York: Oxford University Press, 1989.
4. Ayto, John. Oxford Dictionary of Modern Slang, 2nd ed. New York: Facts on File, Inc., 1997.
5. Evins, Karlen. I Didn't Know That: From "Ants in the Pants" to "Wet Behind the Ears"—The Unusual Origins of the Things We Say. New York: Scribner, 2007.
6. Editors of the American Heritage Dictionary. More Word Histories and Mysteries: From Aardvark to Zombie. Boston, MA: Houghton Mifflin Co., 2006.
7. Harper, Douglas. Etymonline. Last modified 2010. http://www.etymonline.com/.
8. Rawson, Hugh. Devious Derivations. New York: Random House, 1994.
9. Room, Adrian. The Fascinating Origins of Everyday Words. Chicago: NTC Publishing Group, 1986.
10. Garrison, Webb. Casual Lex. Nashville, TN: Rutledge Hill Press, 2005.
11. Barnette, Martha. Dog Days and Dandelions. New York: St. Martin's Press, 2003.
12. Jacobson, John D. Toposaurus: A Humorous Treasury of Toponyms. New York: Wiley, 1990.
13. Urdang, Laurence. The Whole Ball of Wax and Other Colloquial Phrases. New York: Putnam Publishing Group, 1988.
14. Claiborne, Robert. Loose Cannons, Red Herrings, and Other Lost Metaphors. New York: W. W. Norton & Co., 1988.
15. Rees, Nigel. Why Do We Say...? New York: Sterling Publishing Co., 1987.
16. Cousineau, Phil. Wordcatcher: An Odyssey Into the World of Weird and Wonderful Words. Berkeley, CA: Viva Editions, 2010.
