Why did Yakov refer to Lavan as "Lavan ben Nachor" and not 'Lavan ben Besu'el'?
Ramban #1, ha'Emek Davar: Because Nachor, the head of the family, was more important than Besu'el. 1
Ramban #2: It is also possible that Besu'el was a nonentity, and Lavan did want people to attach himself to him, only to his grandfather Nachor. 2
Ramban #3: It may also be that the Torah mentions Nachor, who was the head of the family, in honor of Avraham, whose brother he was.
Moshav Zekenim: It is because the city was called "Ir Nachor."
Yakov could not mention Besu'el's name without calling him "my grandfather 3 " or a title of respect. He did not want to do so, for he was an idolater. (PF)
Besu'el had a bad reputation. 4 (PF)
As we find later (31:53), where Lavan himself referred to "the G-d of Avraham and the god of Nachor".
We find (24:50) "And Lavan and Besu'el answered (Lavan did not esteem his father, and spoke up before him).
It is clear that Kerem Shlomo (8:8 p.8, cited in Daf Al ha'Daf Shabbos 33b) forbids calling one's grandfather by name without a title of respect. I did not find anyone who forbids doing so for a great grandfather. (PF)
Hadar Zekenim (24:33): He would have Bi'ah with every girl before her Chupah; this is why his name is like Besulah. People of his city would have forced him to do so to his own daughter; this is why he wanted to kill Eliezer!