Your definition is misleading and I question your suitability to teach anyone English vocabulary.
You define a maniac as a "lunatic" or "crazy person" with no reference to the dictionary from which you got said definition, but then use words such as pyromaniac, megalomaniac as examples of the word. So that means that it is the definition of a maniac as:

A person who has an excessive enthusiasm or desire for something

from The American Heritage Dictionary of the English Language, 4th Edition

not as a "lunatic" which is:

A person who is affected by lunacy; a mentally deranged person.
from American Heritage Dictionary of the English Language, Fifth Edition

If you don't know the obvious differences between being deranged and having an irresistible compulsion then how can you teach English language?

Also I don't see any etymology of the word here or words which have the same root nor are the synonym and antonyms present. So what kind of education are you actually providing?