From a web posting of the Santa Cruz Public Libraries, found from Google:

Illegitimi Non Carborundum

"Don't let the bastards grind you down"

According to Safire's New Political Dictionary, this is "a pseudo-Latin 
phrase meaning 'don't let the bastards grind you down'. Small signs and plaques 
carrying this message have appeared in U.S. business offices and army posts for 
at least a generation, since General "Vinegar Joe" Stilwell used it as his 
motto in World War II. Carborundum is a trademark for silicon carbide, a leading 
commercial grinding substance...In politics, the motto was popularized by 1964 
Republican nominee Senator Barry Goldwater, who hung the sign in his office." 
(--from Safire's New Political Dictionary, p. 353)

Source: Safire, William Safire's New Political Dictionary : The Definitive 
Guide to the New Language of Politics Random House, New York, 1993. (R 320.03 
Sa1)

Verified by: GM, 5/98

Note: this is NOT found in Bartletts!

Bob Mumford
Darnestown