- a day, varying in date but always in the spring, observed in certain states of the U.S. by the planting of trees.
Origin of Arbor Day
An Americanism dating back to 1870–75
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for arbor day
He made no reply, going on carefully with his arbor-day practice.V. V.'s Eyes
Henry Sydnor Harrison
Word Origin and History for arbor day
the day set aside for the planting of trees, first celebrated 1872 in Nebraska, the brainchild of U.S. agriculturalist and journalist J. Sterling Morton (1832-1902). From Latin arbor "tree," of unknown origin.
Online Etymology Dictionary, © 2010 Douglas Harper