Arbor Day(redirected from Arbour Day)
Also found in: Thesaurus, Encyclopedia.
An unofficial US holiday observed most often on the last Friday in April, for the public planting of trees.
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.
a day in spring observed by the planting of trees.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.