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Prefixes from FOR to ISO

Sample lecture Course syllabus

for- : away, opposite, completely 

forsake (to abandon)

forfeit (to lose something as a fine or penalty)  

forgive (to let go of anger, to cancel debt) 

forgo (to decline to take something pleasant, do without, omit, surrender) 

forlorn (hopeless, pitifully sad, sorrowful)

fore- : in front of, previous, earlier

forebear (an ancestor) 

forebode (to give an advance warning of something bad) 

forecast (a preview of events to be) 

foreshadowing ( a warning or indication of a future event)

foresight (the ability to anticipate what will happen in the future)

hemi- : half, partial

hemicycle (a semicircular structure) 

hemisphere (one half of the earth) 

hyper- : too much, over, excessive, beyond

hyperactive (very restless) 

hypercritical (too critical) 

hypertension (above normal pressure) 

hyperbolic (exaggerated, hyperbolical)

hyperventilate (to breathe at an abnormally rapid rate)

hypo- : less than, under

hypoglycemia (an abnormally low level of sugar in the blood) 

hypothermia (abnormally low body temperature) 

hypothesis (an unproven assumption or claim)   

hypochondria (abnormal anxiety about one's health)

il-, im-, in- : in, into

illuminate (to give light to) 

impact (to come into forcible contact with)

impetuous (into attacking → brandish, rash)

imperil (to put at risk of being harmed)

impregnate (make a woman pregnant)

incendiary (causing fires, inflammable, provocative)

innovation (a new idea, method, or device) 

inspection (the act of examining or reviewing) 

incarnate (embodied in flesh, represented in the most extreme form) 

inception (establishment, formation)

ig-, il-, im-, in-, ir- : not, without

ignoble (not noble, dishonorable)

ignominious (losing good name, disgraceful, shameful)

illegal (not legal) 

illiberal (not liberal)

illicit (not legitimate)

immaculate (without stain, clean, spotless, unblemished, pure)

immediate (without intervention, instant, prompt, speedy)

impecunious (without money, poor)

impossible (not possible)

impudent (not showing due respect for another person; impertinent)

impunity (no punishment, immunity, indemnity) 

inappropriate (not appropriate)

insecure (not secure)

incompetent (not competent)

innocuous (not harmful or offensive)

irresponsible (not responsible)

irregular (not regular)

infer- : below

inferior (lower in rank, status, or quality)  

infernal (of hell, hellish, lower)

inferno (a large fire that is dangerously out of control, hell)

infra- : beneath, below 

infrastructure (underlying framework of a system) 

infrared (below the regular light spectrum) 

inter- : between, among, jointly

international (involving two or more countries) 

intersection (place where roads come together) 

intercept (to stop or interrupt the course of) 

interim (the intervening time)

intermittent (occurring at irregular intervals)


intra-,  intro- : within, inside

intrastate (existing in one state) 

intravenous (inside or into a vein) 

introvert (shy person who keeps within him or herself)

introspection (self-reflection, contemplation)

iso- : equal

isotopes (elements with equal protons but different neutrons) 

isosceles (a triangle with two sides of equal length)