index fingern.1. The finger next to the thumb.2. The part of a glove that covers this finger. In both senses also called first finger, forefinger.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.index finger n (Anatomy) the finger next to the thumb. Also called: forefinger Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014fore?fin?ger (?f?r?f?? g?r, ?fo?r-) n. the finger next to the thumb. Also called index finger. [1400?50] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.