aspect ration.1. The width-to-height ratio of an image or of the area used to display an image. Most widescreen televisions have an aspect ratio of 16:9.2. The span-to-mean-chord ratio of an airfoil.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.aspect ratio n 1. (Electronics) the ratio of width to height of the picture on a television or cinema screen 2. (Aeronautics) aeronautics the ratio of the span of a wing to its mean chord Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014as?pect ra`tio n. 1. the ratio of the span of an airfoil to its mean chord. 2. the ratio of the width of a televised or computer-screen image to its height. [1905?10] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.