Using "Polybus' son" to refer to "Oedipus" is an example of a patronymic.
Explanation:
A patronymic is a part of the individual’s name supported by the name of one's father, grandfather, or earlier male ancestor.
Similarly part of the name supported by the name of one's mother or female ancestor is known as matronymic.
The name of the person supported by the name of one's child is a teknonymic.
