(Latin: in, into, within, inside, on, toward [il-, ir-, im-], in, into, etc.: involve, incur, invade; also, used intensively, as in the words inflame and inflammable, or without perceptible force.)

The in- changes or is assimilated to il- before l, as with "illuminate", to im- before b, as with "imbibe"; before m, as with "immediate"; before p, as with "implant"; and to ir- before r, as with "irrigate".

The form generally remains unassimilated in words formed in English; such as, inbreed.

Don't confuse this in-2, meaning "in, into, within", etc. with the Latin prefix in-1 meaning "not" nor with the prefix for English-origin words in-3 meaning "in, into; within".

illuminate (verb), illuminates; illuminated; illuminating
1. To make something visible or bright with effulgence, or be lit up: Esther sat near the window so the sunlight would illuminate her sewing better and she could then easily fasten the buttons on the shirt.
2. To decorate something with lamps for a celebration: The youth groups planned to illuminate the statues in the city park with bright lanterns in time for the holidays.
3. To make something clear, or easier to understand and to appreciate: Dr. Murphy's explanation was illuminating on the subject of portrait photography and so Jim was able to appreciate black and white portraits easier.

Footnotes illuminated the difficult definitions in the dictionary of scientific terms.

4. To add colored letters, illustrations, and designs to a manuscript or the borders of a page: In the ancient monasteries, the resident monks used their time and skills to illuminate manuscripts, enhancing the beauty of the words with the beauty of the pages.
5. To provide someone with knowledge or with intellectual or spiritual enlightenment: Mary Jo went on a spiritual retreat for the weekend and felt illuminated by the workshops and lectures she attended.
imbibe, imbibed
1. To drink.
2. To drink alcoholic beverages.
3. To absorb or take in as if by drinking: “The whole body ... imbibes delight through every pore” (Henry David Thoreau).
4. To receive and absorb into the mind: “Gladstone had ... imbibed a strong prejudice against Americans” (Philip Magnus).
5. To permeate; saturate.
immigrate (verb), immigrates; immigrated; immigrating
1. To go to a new nation for the purpose of living there or to establish them as permanent residents: To immigrate is the movement that is related to a different destination or going into another geographical area.
2 In botany and zoology; to become established in a new environment.
import (verb), imports; imported; importing
To carry or to bring in products; such as, goods brought in from abroad: Horace was importing glass from Italy when he first set up his import and export business.
inaugurate (verb), inaugurates; inaugurated; inaugurating
1. To make a formal beginning of; to initiate; to commence; to begin: "The end of World War II inaugurated the era of nuclear power."
2. To induct into office with formal ceremonies; to install: "The President of the U.S. was inaugurated for his second term in office."
A Roman priest interprets the flight of the birds as good or evil.

When we speak of the inauguration of a president, we use a word that carries us back to ancient times when people believed in omens, or signs that indicate what will happen in the future, and looked for them on every important occasion; however, the ceremony of inauguration today does not call for the observation of such predictions.

—The image and text is compiled from
Picturesque Word Origins; Webster's New International Dictionary;
G. & C. Merriam Company; Springfield, Massachusetts, U.S.A.; 1933; pages 70-71.

3. To introduce into public use by some formal ceremony: "Airmail service between Washington, D.C., and New York City was inaugurated in 1918."
4. Etymology: From Latin inaugurātus; past participle of inaugurāre, "to consecrate by augury" (a person chosen for the priesthood or other office; literally, "to take auguries").

The word inaugurate has its roots in the Latin term meaning, "to practice augury". In ancient Rome, a select few priests were charged with observing the flight and feeding of birds in order to discover signs of the future.

Such observations were known as auguries, and the practitioners of this art as augurs. For a few hundred years, the now-obsolete augurate meant, "to make an augury".

Presumably, it was the ceremonial connotation of auguring and not its "foretelling aspects" that brought inaugurate into print in English in 1606, with the meaning, "to induct into an office with suitable ceremonies".

incandescent (adjective), more incandescent, most incandescent
1. Descriptive of bright, and glowing with light or heat.
2. Relating to something that is shining brilliantly.
. 3. Characterized by ardent emotion, intensity, or brilliance: The singer had an incandescent performance.
inflammable (adjective), more inflammable, most inflammable
1. Something that is quickly and easily set on fire and burned; combustible: To keep themselves warm in the living room, Mr. Thompson used inflammable wood so that the family could enjoy the blazing flames in the hearth.
2. Easily aroused or excited, as to passion or anger; irascible: Her father had an inflammable disposition regarding the men she was dating.
1. To write, mark, or delineate (words, a name, characters, etc.) in or on something; especially, so as to be conspicuous or durable, as on a monument, tablet, etc.
2. To write or enter the name of (a person) upon an official document or list; to enroll.
3. To dedicate (a writing or work of art) to a person by a short inscription (placed at the beginning of a writing, or beneath a picture, etc.), less formal than an ordinary dedication.
insist (verb), insists; insisted; insisting
1. To demand that something happens or that a person does something: Jillian didn't want to go to the dentist, but her husband insisted because she stumbled and fell against a wall and broke her two front teeth.
2. To say something in a very forceful way which doesn't allow for any disagreement: Henry insisted that his son didn't mean to be impolite when he disagreed with what his aunt said about his web site.

The couple next to Karl and Janine insisted on talking during the movie.

insistence (s) (noun), insistences (pl)
1. A forceful and pressing demand: Mr. Jones spoke with extraordinary insistence on helping the poor people in the city.
2. The act of being persistent and unremitting: Mrs. Smart always expected her students to do their best and her insistence on this proved to be correct!
insistent (adjective); more insistent, most insistent
1. Concerning the demand of attention: When baby Susi was hungry, she was very insistent about getting her meal by crying loudly!
2. Persistent; continual; unrelenting: Greg woke up with the insistent and urgent ringing of his alarm clock.
insistently (adverb); more insistently, most insistently
Descriptive of how someone says something in a demanding or pressing way: Little baby Susi cried insistently because she was so very hungry.
intricate (IN truh kayt", IN tree kayt") (verb), intricates; intricated; intricating
1. To entangle; to involve; to make complicated: When Doris presented her report to her biology class, the students accused her of intricating it with too many incomprehensible terms that they never heard of before.
2. Etymology: from Latin intricare, "to entangle, to perplex"; from in-, "in, into" + tricare, "to trick, to complicate, to perplex".