Do we need to change the definition of "Science"??

Your statement about falsifiability is a bit off. A good scientific theory is falsifiable if one can propose a test that could find the theory incorrect if the test were done. If the test is performed, the theory could be found to be false, or the test could provide more support for the theory. This does not imply that a good scientific theory can be discredited. It means that the theory is so precise that one can do the test.