any of certain
clovers or cloverlike plants with leaflets in groups of three, used as the emblem
of Ireland, as the red clover, white clover, wood sorrel, or black medic
Webster’s New World College Dictionary, 4th Edition. Copyright © 2010 by
Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'shamrock'Ir seamrog, dim. of seamar, clover