Something that is deeply disgraceful is ignominious (ig nuh MIN ee us):
- Lola’s    plagiarizing    of  Nabokov’s   work    was an  ignominious act that    got her suspended
from school for two days. 
IMPUGN (im PYOON) v to attack, especially to attack the truth or integrity of something
- The   critic  impugned    the originality of  Jacob’s novel,  claiming    that    long    stretches   of  it  had
been lifted from the work of someone else. - Fred  said    I   was impugning   his honesty when    I   called  him a   dirty   liar,   but I   told    him he  had
no honesty to impugn. This just seemed to make him angrier. 
IMPUNITY (im PYOO nuh tee) n freedom from punishment or harm
- All   students     were    expected    to  follow  the     rules   with    the     exception   of  the     headmaster’s
son, who was treated with impunity; no matter how many rules he broke, he never got
detention. 
INDICT (in DYTE) v to charge with a crime; to accuse of wrongdoing
- After  a   five-day    water   fight,  the     entire  freshman    dorm    was    indicted     on  a   charge  of
damaging property. - The   mob boss    had been    indicted    many    times,  but he  had never   been    convicted   because
his high-priced lawyers had always been able to talk circles around the district attorney. 
An act of indicting is an indictment.
- The broken fishbowl and missing fish were a clear indictment of the cat.
 
INDIGNANT   (in DIG nunt)   adj     angry,  especially  as  a   result  of  something   unjust  or  unworthy;
insulted
- Ted    became indignant    when    the     policewoman     accused     him     of  stealing    the     nuclear
weapon. - Isabel    was indignant   when    we  told    her all the nasty   things  that    Blake   had said    about   her
over the public address system. 
INTRACTABLE (in TRAK tuh bul) adj uncontrollable; stubborn; disobedient
- Lavanya   was intractable in  her opposition  to  pay increases   for the library employees;  she
swore she would never vote to give them a raise. - The   disease was intractable.    None    of  the dozens  of  medicines   the doctor  tried   had the
slightest effect on it. 
The opposite of intractable is tractable.
LUCID (LOO sid) adj clear; easy to understand
- The   professor’s explanation of  the theory  of  relativity  was so  astonishingly   lucid   that    even
I could understand it.