Answer:
Measurable response(s) (dependent variables) of something we are studying
Explanation:
Simply put, in Statistics, Mathematics, etc. response variable in a experiment is the measurable response(s).
In other words, response variable can be measured, quantified. This kind of variables are widely known as Dependent Variable.
In an experiment, we have the object of study with Independent Variables exerting influence as factors. Response Variables, or simply responses are affected by these factors.