Technically speaking, the term 'defensive driving' is defined: "driving to save lives, time, and money, in spite of the conditions around you and the actions of others.' This definition is from Safe Practices for Motor Vehicle Operations, a publication from the American Society of Safety Engineers. In layman's terms, it means operating a motorized vehicle in a manner that anticipates driving situations before they happen rather than reacting after the fact.
There are many good defensive driving tips. These include the following: