Black Shirt also Black·shirt (bl?k?shûrt?)n. A member of a fascist party organization having a black shirt as part of its uniform, especially an Italian fascist.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.Black? Shirt` n. a member of a fascist organization, esp. the Italian Fascist militia, wearing a black shirt as part of the uniform. [1920?25] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.