Polymorphism Phone Interview Question

Question

So my question is not WHAT IS POLYMORPHISM? I know what the defnition of Polymorphism is

But how to answer the question in a phone  interview when the interviewer says,

Were and how did you achieve polymorphism? How to answer that question without stumbling?

Can someone give me a and explicit answer as how you would answer this in an interview and apply it to the STAR method approach below?

  You can make up a fake company or task and apply the example you use above into the star method. Also make your response past tense, as if it already happen. I am more concern of what did yo do. How to explain what did you do, not how can you. Explaining how can you is simple to me.

S- Situation (While working for company X.........)

T-Task (For this particular task I was responsible for......)

A-Action (The actions I took.......)

R-Result (The system implemented as team ........)