aim·less (?m?l?s)adj. Lacking direction or purpose: an aimless stroll; aimless slackers.aim?less·ly adv.aim?less·ness n.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.