The definition of the word bad.

What do we mean by the word bad? Do we use it with correct terminology? The definition to the word bad in the 'Concise English Dictionary' is.... not good, wicked, immoral injurious and incompetent.
An individuals opinion of what actually is 'being bad' influences when and how we choose to use it. Examples of when we use the adjective in everyday language are:

1/ "You bad girl"

2/ I was impressed, the essay wasn't too bad!

3/ Too much alcohol is bad for you!

The word 'bad' has several meanings as illustrated in the above sentence.