infuse v. to put into or introduce as if by pouring; to fill or cause to be filled with something; to introduce (a solution) into the body through a vein for therapeutic purposes

ingest v. to take into the body by the mouth for digestion or absorption; to take in and absorb as food

ingratiate v. to bring (oneself, for example) into the favor or good graces of another, especially by deliberate effort

ingratitude n. lack of gratitude; ungratefulness

ingredient n. component; element; factor; one of the substances which comprises a mixture

inhabit v. to occupy; to live in; to dwell in; to reside in; to populate

inhabitant n. person who lives in a particular place; resident; tenant; occupant

inherent adj. intrinsic; existing as a natural and integral part; natural; inborn

inhibit v. to hold back; restrain; to prohibit; forbid

initial n. beginning letter of a person's first name; first letter (as of a word)

initial v. to sign using the first letter or letters of a name

initialed adj. signed with initials; marked with the first letter or letter of a name

initially adv. at first; in the first place; at the beginning

initiate v. to set going; to launch; to begin; to start

initiative adj. beginning; introductory

initiative n. enterprise; drive; ambition; beginning move in a process; first step

inject v. to force or drive (a fluid) into something; to introduce (a drug or vaccine, for example) into a body part, especially by means of a syringe; to introduce into conversation or consideration; to place into an orbit, trajectory, or stream

injection n. the act of injecting; something that is injected, especially a dose of liquid medicine injected into the body

innocent adj. not guilty; free from sin or wrongdoing; pure; simple; naive; unsophisticated; harmless

innocent n. person who is free from sin or wrongdoing; person who is simple or naïve

innovate v. to make changes; to create something new; to invent

innovation n. introduction of something new; change; new method or practice

innovator n. person who makes changes; person who introduces new methods or procedures; creative person

innumerable adj. too numerous to be counted; numberless

inquiry n. formal question; exploration; questioning; investigation

inscribe v. to write, print, carve, or engrave (words or letters) on or in a surface; to enter (a name) on a list or in a register; to sign one's name or write a brief message in or on (a gift book or photograph, for example)

insecticide n. A chemical substance used to kill insects

insist v. to demand; to emphasize firmly; to request firmly; to require; to persevere

inspect v. to check; to look over carefully and critically; to examine officially; to review

inspection n. act of looking over carefully and critically; official examination; audit; review

inspector n. person whose job it is to supervise and examine; police officer ranking below a superintendent

inspiration n. something which stimulates or animates; stimulus; motivation; something inspired; revelation; insight; idea

inspire v. to motivate; to stimulate; to provoke; to influence; to encourage; to cause

inspiring adj. motivating; stimulating; animating; encouraging; provoking; breathing in; inhaling

install v. to set up for use; to put in (i.e. machinery); to establish in an office or position

installment n. one of several separate payments into which a debt has been divided

instance n. occurrence; occasion; example; illustration; prosecution of a case; urgency; pressing importance

instance v. to refer to a case or occurrence to explain or prove a point; to cite; to mention

instant adj. immediate; quick; urgent; pressing; quickly prepared; needing little work or effort to be ready; present; current

instant n. moment; very short space of time; present moment; food or beverage which can be prepared in a very short amount of time

instantaneous adj. immediate; momentary

instill v. to introduce by gradual, persistent efforts; implant; to pour in (medicine, for example) drop by drop

instinctively adv. naturally; spontaneously; intuitively; automatically

institute n. institution; foundation; organization which provides a certain service or supports a particular cause; college which specializes in a particular field or area or instruction (i.e. art)

institute v. to establish; to found; to set up; to begin; to initiate; to start

institution n. organization; custom; convention; law or activity which is accepted in a society

instruct v. to inform; to direct; to guide; to command; to order; to educate; to teach

instructor n. educator; teacher; trainer

instrument n. tool, implement; device; appliance; musical instrument; agent; means; document

instrument v. to equip with devices for measuring, recording, or controlling

insulate v. to separate from others; to segregate

insult n. affront; offense; rude remark or action

insult v. to speak or act in a rude or contemptuous manner; to offend; to affront

insurance n. contract by which property or persons are guaranteed against damage or loss; something which protects or guarantees safety

insure v. to provide a guarantee against possible damage or loss; to make certain

intangible adj. incapable of being perceived by the senses; incapable of being realized or defined

integrate v. To make into a whole by bringing all parts together; unify; to join with something else; unite

integrity n. honesty; uprightness; morality; wholeness; unity; unimpaired condition

intellectual adj. rational rather than emotional; appealing to or engaging the intellect

intellectual n. an intellectual person

intelligence n. ability to reason and understand; cleverness; brilliance; knowledge; information; collecting of information

intelligible adj. capable of being understood; capable of being apprehended by the intellect alone

intense adj. extreme; great; powerful; high; strong; profound; deep; acute; severe

intensify v. to increase; to strengthen; to heighten

intensity n. strength; energy; extreme degree; depth; clarity

intensive adj. characterized by a high degree; highly concentrated

intention n. determination to do something in particular; plan; aim; goal; purpose; meaning; import; significance

interact v. to act on each other

intercept v. to stop, deflect, or interrupt the progress or intended course of

interchangeable adj. can be traded; can be substituted by something else

interfere v. to impede; to obstruct; to hinder; to meddle; to intrude in the affairs of other; to collide; to block

interim adj. temporary; provisional

interim adv. meanwhile; in the meantime

interim n. temporary arrangement; in between period

interior adj. inner; inside; of something which is inside; inland; of a country's domestic affairs; of an individual's inner life

interior n. inside; inside a building; inland section of a country

interject v. to place between other things; to throw into the center of; to interpolate; to insert a remark or comment in the middle of a conversation

interminable adj. being or seeming to be without an end; endless; tiresomely long; tedious

intermittent adj. not continuous; sporadic; fitful; alternately stopping and starting

internal adj. inner; inside; located within; of a country's domestic affairs; of an individual's inner life; private; mental

internal n. inner quality; intrinsic characteristic

international adj. between countries; involving or belonging to two or more countries; of relations between two or more countries

internationalize v. to bring under the jurisdiction of two or more nations; to globalize; to make worldwide

interpret v. to explain; to clarify; to elucidate; to translate from one language to another (orally); to understand or explain in a particular way; to translate from one language to another (orally)

interpreter n. person who translates from one language to another (orally); person how clarifies; commentator

interrupt v. to stop; to discontinue; to disturb; to bring a conversation to a halt

interruption n. disturbance; disruption; discontinuance; stoppage; cutting-off

intersection n. the act, process, or result of intersecting; a place where things intersect, especially a place where two or more roads cross

intimidate v. to make timid; fill with fear; to coerce or inhibit by or as if by threats

intricate adj. complex; complicated; involved; entangled

intrigue n. a secret or underhand scheme; a plot

intrigue v. to engage in secret or underhand schemes; plot

introductory adj. preliminary; beginning; serving as an introduction

invade v. to enter by force in order to conquer or pillage; to encroach or intrude on; violate

inventory n. stock; list of assets; act of checking stock

investigate v. to observe or inquire into in detail; examine systematically

invincible adj. incapable of being overcome or defeated; unconquerable

invisible adj. impossible to see; imperceptible; hidden; concealed

invoke v. to call on (a higher power) for assistance, support, or inspiration; to appeal to or cite in support or justification; to resort to; use or apply

involve v. to cause to be concerned with; to entangle; to engage; to engross; to complicate; to incriminate

involvement n. inclusion; participation; connection; association; complexity; entanglement; relation; participation

irrelevant adj. not relevant; beside the point; unconnected; impertinent; immaterial

irritate v. to annoy; to bother; to aggravate; to anger

irritated adj. annoyed; aggravated; exasperated

irritation n. something which annoys or aggravates

issue n. topic; subject; matter; question; problem; end result; publication (i.e. newspaper, magazine, newsletter, etc.); act of sending out; distribution

issue v. to publish; to distribute; to circulate; to come forth; to put out; to emit; to result from

itemize v. to catalog; to list; to enumerate; to set down in full detail

itinerary n. route; travel route; travel plans; travel journal; record of a journey; travel guidebook