I’d (?d)1. Contraction of I had.2. Contraction of I would.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.I’d (a?d) contraction ofI had or I wouldCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014id (?d) n. Psychoanal. the part of the psyche that is the source of unconscious and instinctive impulses that seek satisfaction in accordance with the pleasure principle. Compare ego (def. 2), superego. [1924;