Definition of "leap year" []

• A year in the Gregorian calendar having 366 days, with the extra day, February 29, intercalated to compensate for the quarter-day difference between an ordinary year and the astronomical year. (noun)
• An intercalary year in a calendar. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.