What does it mean for a friend not to answer the phone or return the text message?

No matter what the other person means, if the other person doesn't answer the phone or respond at this time, there is absolutely no need for such a friend to pay attention to the other person. At this time, the other party may deliberately avoid you and don't want to have too much contact with you.

Of course, in this case, if you only make a phone call for a period of time, and the other party doesn't answer the phone or return the message, there is generally no problem, for example, within an hour or two, because in this case, the other party may be busy with his own reality, such as work or other things, and it is normal to not hear at this time, so it is necessary to understand the other party at this time.

Of course, if we call his mother for several days or more at this time, and one party doesn't reply, then there is absolutely no need to pay attention to the other party for such a relationship, so at this time, we should safeguard our dignity. If the professor ignores each other, it is also a maintenance of our dignity. So don't have any hope at this time and leave decisively.