Theory:

Antonyms are words that have the exact opposite meaning of another word.
Good_Bad (1)-w2918.png
 
Antonyms derive their name from the word "anti" meaning "opposite" and "onym" meaning "name".
Antonyms are important because it helps to understand the exact meaning of the word given. To understand the meaning of a word, we can also take a look at the antonym or the opposite word. It helps us to find the exact meaning from diverse meanings, from the opposite point of view.
Important!
It may be interesting to note that most dictionaries present the meaning, synonyms and antonyms of words for a clear understanding.
Example:
Let us take up the case of the word "beautiful".
  • The dictionary meaning is "pleasing the senses or mind aesthetically". Synonyms are "lovely, pretty, good-looking" and the antonym is "ugly".
  • The antonym expresses the opposite meaning, and it is precise. It helps to understand the word "beautiful" from a reverse perspective also.
Important!
Click here for an extensive list of antonyms.
Antonyms of words from the lesson "An Indian-American woman in space - Kalpana Chawla" and a few others with different prefixes are given below:
 
No.WordAntonym
1
IdentifiedUnidentified
2
SuccessfulUnsuccessful
3
AttendedUnattended
4
ControlledUncontrolled
5
ImportantUnimportant
6
CountableUncountable
7
ControlledUncontrolled
8
TrainedUntrained
9
QualifiedUnqualified
10
AnswerableUnanswerable
11
CredibleIncredible
12
CompleteIncomplete
13
VisibleInvisible
14
Accurate Inaccurate
15
FormalInformal
16
AdvantageDisadvantage
17
OrderlyDisorderly
18
HonestDishonest
19
SatisfiedDissatisfied
20
AppearDisappear
21
ContinueDiscontinue
22
MovableImmovable
23
MatureImmature
24
MobileImmobile
25
PertinentImpertinent
26
PatientImpatient
27
ResponsibleIrresponsible
 
Important!
To know more about antonyms, click here.