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–id 1
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suff.
1. One belonging to a specified dynastic line: Abbasid.
2.
a. Meteor associated with or appearing to radiate from a specified constellation or comet: Perseid.
b. Member of a class of stars typified by a certain star in a specified constellation: Cepheid.
3. Organism belonging to a specified taxonomic group, often a family having a name ending in -idae according to taxonomic principles or a class or other taxon having a name ending in -idae: cichlid, magnoliid.

[Latin -idēs, from Greek, patronymic suffix. Senses 2 and 3, from New Latin -idae, from plural of Latin -idēs.]

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
ID 1 (īdē) Informal
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n.
A form of identification, especially an ID card.
tr.v. ID'ed, ID'·ing, ID's
To check the identification of, especially in order to verify legal age; card: The bouncer ID'ed everyone who looked younger than 30.

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
–id 2
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suff.
Body; particle: chromatid.

[Latin -is, -id-, feminine patronymic suff., from Greek.]

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
ID 2
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abbr.
1. also Id. Idaho
2. identification
3.
a. inner diameter
b. inside diameter
c. internal diameter
4. Intelligence Department
5. intelligent design

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
'Id (ēd)
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n.
Variant of Eid.

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
id.
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abbr.
idem

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
id (ĭd)
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n.
In psychoanalytic theory, the division of the psyche that is totally unconscious and serves as the source of instinctual impulses and demands for immediate satisfaction of primitive needs.

[New Latin (translation of German Es, a special use of es, it, as a psychoanalytic term), from Latin, it; see i- in the Appendix of Indo-European roots.]

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 

Indo-European & Semitic Roots Appendices

    Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

    Indo-European Roots

    Semitic Roots

    The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

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