1) Analytic philosophy 
Falsifiability or refutability of a statement, hypothesis, or theory is an inherent possibility to prove it to be false. A statement is called falsifiable if it is possible to conceive an observation or an argument which proves the statement in question to be false. In this sense, falsify is synonymous with nullify, meaning not `to commit fraud`.....
A claim (or theory) is falsifiable if and only if there is some possible empirical observation which could show that it is false.
The ability of a theory or hypothesis to be rejected.