oak leaf cluster
a U.S. military decoration in the form of a small bronze twig bearing four oak leaves and three acorns, worn on the ribbon of another decoration for valor, wounds, or distinguished service to signify a second award of the same medal.
Origin of oak leaf cluster
An Americanism dating back to 1915–20
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019