What is the definition or description of: bad circulation?

Depends: This is a gernalized term and usually indicates poor arterial perfusion to an extremity. However, in my experience, docs also use it to indicate venous problems as well.

Poor perfusion: You have hardening of the arteries probably caused by cholesterol deposits in your blood vessels. Since thecalliber of your blood vessels have narrowed the flow of blood has slowed and your tissues and organs are not being perfused as well.