noon (no?on)n.1. a. Twelve o’clock in the daytime; midday.b. The time or point in the sun’s path at which the sun is on the local meridian. Also called noontide, noontime.2. The highest point; the zenith.3. Archaic Midnight.[Middle English non, from Old English n?n, canonical hour of nones (3 pm in early Middle Ages), from Late Latin n?na (h?ra), ninth (hour after sunrise), nones, feminine sing. of Latin n?nus, ninth; see newn? in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.noon (nu?n) n1. a. the middle of the day; 12 o’clock in the daytime or the time or point at which the sun crosses the local meridianb. (as modifier): the noon sun. 2. poetic the highest, brightest, or most important part; culmination[Old English n?n, from Latin n?na (h?ra) ninth hour (originally 3 p.m., the ninth hour from sunrise)]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014noon (nun) n. 1. midday. 2. twelve o’clock in the daytime. 3. the highest, brightest, or finest point or part. 4. Archaic. midnight. [before 900; Middle English none, Old English n?n