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in- 1 or il- or im- or ir-
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pref.
Not: inarticulate. Before l, in- is usually assimilated to il-; before r to ir-; and before b, m, and p to im-. See Usage Note at un-1.
[Middle English, from Old French, from Latin; see ne in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
in 1 (ĭn)
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prep.
1.
a. Within the limits, bounds, or area of: was hit in the face; born in the spring; a chair in the garden.
b. From the outside to a point within; into: threw the letter in the wastebasket.
2. To or at a situation or condition of: was split in two; in debt; a woman in love.
3.
a. Having the activity, occupation, or function of: a life in politics; the officer in command.
b. During the act or process of: tripped in racing for the bus.
4.
a. With the arrangement or order of: fabric that fell in luxuriant folds; arranged to purchase the car in equal payments.
b. After the style or form of: a poem in iambic pentameter.
5. With the characteristic, attribute, or property of: a tall man in an overcoat.
6.
a. By means of: paid in cash.
b. Made with or through the medium of: a statue in bronze; a note written in German.
7. With the aim or purpose of: followed in pursuit.
8. With reference to: six inches in depth; has faith in your judgment.
9. Used to indicate the second and larger term of a ratio or proportion: saved only one in ten.
adv.
1. To or toward the inside: opened the door and stepped in.
2. To or toward a destination or goal: The mob closed in.
3. Sports So as to score, as by crossing home plate in baseball: singled the runner in.
4. Within a place, as of business or residence: The manager is in before anyone else.
5. So as to be available or under one's control: We can proceed when all the evidence is in.
6. So as to include or incorporate: Fold in the egg whites.
7. So as to occupy a position of success or favor: campaigned hard and was voted in.
8. In a particular relationship: got in bad with their supervisor.
adj.
1. Located inside; inner.
2. Incoming; inward: took the in bus.
3. Holding office; having power: the in party.
4. Informal
a. Currently fashionable: the in thing to wear this season.
b. Concerned with or attuned to the latest fashions: the in crowd. See Synonyms at fashionable.
5. Relating to, understandable to, or coming from an exclusive group: an in reference.
n.
1. One that has position, influence, or power: the ins against the outs.
2. Informal Influence; power: had an in with the authorities.
Idioms:
in for
Guaranteed to get or have: You're in for a big surprise.
in on
Informed about; participating in: Only one business partner was not in on the illegal scheme.
in that
For the reason that.
[Middle English, from Old English; see en in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
in- 2 or il- or im- or ir-
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pref.
1. In; into; within: inundation. Before l, in- is usually assimilated to il-; before r to ir-; and before b, m, and p to im-.
2. Variant of en-1.
[Middle English, from Old English (from in, in; see IN1) and from Old French (from Latin, from in, in, within; see en in the Appendix of Indo-European roots).]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
in 2 or in.
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abbr.
inch
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
IN
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abbr.
Indiana
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
In
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The symbol for indium.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
-in
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suff.
1. Neutral chemical compound, especially:
a. Neutral carbohydrate: inulin.
b. Protein or protein derivative: albumin.
c. Lipid or lipid derivative: lecithin.
d. Enzyme: pancreatin.
e. Glycoside: chitin.
2. A pharmaceutical: rifampin.
3. An antibiotic: penicillin.
4. Antigen: tuberculin.
5. Variant of -ine2.
[Variant of -INE2.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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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