male pattern baldnessn. Progressive loss of scalp hair in men that usually begins in early adulthood and characteristically leads to loss of hair on the crown and above the temples; androgenetic alopecia. Also called male pattern hair loss.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.