adage (n.) Look up adage at Dictionary.com
"brief, familiar proverb," 1540s, Middle French adage, from Latin adagium "adage, proverb," apparently from adagio, from ad- "to" (see ad-) + *agi-, root of aio "I say," from PIE *ag- "to speak." But Tucker thinks the second element is rather ago "set in motion, drive, urge."