fin·ger·breadth (f?ng?g?r-br?dth?)n. The breadth of one finger.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.fingerbreadth (?f?????br?d?; -?br?t?) or finger’s breadthn (Units) the width of a finger, used as an indication of lengthCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014fin?ger?breadth (?f?? g?r?br?d?, -?br?t?) n. the breadth of a finger: approximately ¾ in. (2 cm). [1585?95] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.