What is Object Eclipsing?

Question

This is a question my interviewer asked me. My Answer is -

if we assign an object of the derived class to the reference of the base class , the members of the derived class will eclipse or hide.

he didn't tell it's wrong or right. I want to confirm it.

Answer 1

There is no such concept "object eclipsing".

Answer 2

I don't know, nor it seems does Google...

Answer 3

Maybe the interviewer meant to say slicing?

That, or it was a trick question.