pi·lar (p??l?r)adj. Of, relating to, or covered with hair.[New Latin pil?ris, from Latin pilus, hair.]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.pilar (?pa?l?) adj (Medicine) med of or relating to the hair, or covered with hairCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014pi?lar (?pa? l?r) adj. of, pertaining to, or covered with hair. [1855?60;