Negative

Negative may mean:

Something negative can be something bad.
A negative number is a number that is less than zero. 5 - 8 = -3.
Some people also use negative the same way as "no", or other related words. "Not", "Never", "Nowhere" etc. are all negative words. On two-way radios the word "negative" is used instead of "no" to be clearer. 
In film photography, a film negative is an exposed picture or movie film that has been processed, and is ready to be used to make a print. In a negative, everything in the picture has the opposite color. Things that are white will be black, things that are red will be green, and things that are orange will be blue.
Negative binary numbers
Negative charge
Negative exponent
Negative feedback, a basic concept of cybernetics; it is the basis of regulation and control. It is important in engineering and physiology. In biology and physiology negative feedback is known as homeostasis
Negative gravity