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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.


contraction of
I had or I would
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014



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; < Latin id it, as a translation of German Es literally, it]



n., pl. ID's, IDs
v., ID'd or IDed or ID'ed, ID'ing or ID•ing.
1. a means of identification, as a document containing information regarding the bearer's identity.
2. to identify.
3. to issue an ID to: Go to the admissions office if you haven't been ID'd yet.


1. Also, Id. Idaho.
2. Also, i.d. inside diameter.
3. (Iraq) dinar.


contraction of I would or I had.


a suffix of nouns that have the general sense “offspring of, descendant of,” occurring orig. in loanwords from Greek (Atreid; Nereid), and productive in English on the Greek model, esp. in names of dynasties, with the dynasty's founder as the base noun (Abbasid; Fatimid), and in names of periodic meteor showers, with the base noun usu. denoting the constellation or other celestial object in which the shower appears (Perseid).
[< Latin -id-, s. of -is < Greek]


a suffix occurring in English derivatives of modern Latin taxonomic names, esp. zoological families and classes; such derivatives are usu. nouns denoting a single member of the taxon or adjectives with the sense “pertaining to” the taxon: arachnid; canid.
[< Greek -idēs]


var. of -ide: lipid.


a suffix occurring in descriptive adjectives borrowed from Latin, often corresponding to nouns ending in -or1: humid; pallid.
[< Latin -idus]




1. identification.
2. identity.
3. Intelligence Department.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in classic literature ?
Half the time, though, I'd forget, I'd be in such a hurry to get into bed nice and quiet and imagine things."
The secretary of the Acme Club warned me I'd have my hands full.
"But I wasn't thinking of asking you to buy me another horse; I was only thinking I'd lost the means of paying you with the price of Wildfire, as I'd meant to do.
"You don't know me again, I doubt," he went on, as Tom continued to look at him inquiringly; "but I'd like to talk to you by yourself a bit, please."
I'd like it to end unhappily, because that would be so much more romantic.
I thought o' you sometimes, and thought I'd come to you, for I didn't think you'd be cross with me, and cry shame on me.
"If I could have my way, I'd blow up all your gods with dynamite."
"Yes, it is -- and I could a had it if I'd been big enough; I see him FIRST.
"If I'd supposed you'd 'a' made any objection to Jotham Powell's driving me over-" she began again, as though his silence had implied refusal.
"I didn't think I'd ever see you again," he said at last.
"Five years ago you drove me away from your father's kitchen one night, when I come to ask for something to eat, and you said I warn't there for any good; and when I swore I'd get even with you if it took a hundred years, your father had me jailed for a vagrant.
I'd much rather be married to a painter than to a stockbroker.