Iconoclast
one who attacks traditional beliefs
Idealist
someone that is unrealistic and impractical in their beliefs
Idiosyncrasy
peculiarity of temperament, eccentricity
Ignoble
having low moral standards, not noble in character, mean
Ignominious
disgraceful and dishonorable
Ilk
type or kind
Illegible
unreadable
Illuminate
fill with light
Illusory
producing illusion, deceptive
Illustrate
provide an example, explain
Imbibe
to receive into the mind and take in, absorb
Imbue
to infuse, to dye, wet, moisten
Imitate
copy, impersonate
Immoderate
excessive
Immunity
invulnerability, exemption
Immutable
unchangeable, invariable
Implausible
improbable, inconceivable
Implement
carry out, put into effect
Importunate
troublesomely urgent, extremely persistent in request or demand
Importune
to ask repeatedly, beg
Impotent
ineffective, lacking strength
Imprecation
a curse
Impressionable
easily influenced or affected
Improvident
without planning or foresight, negligent