What is the meaning of "v'Nigash ha'Am"?
Rashi: They will pressure each other with quarrels and bans. Malbim - they will do so even to their friends.
Radak: This is another curse. People will not be subdued due to their officers and rulers. Rather, everyone will make himself a taskmaster and policeman with his sword, even a small person over a great person.
Radak citing Targum Yonasan: They will fight.
What is the meaning of "Yirhavu ha'Na'ar ba'Zaken"?
Rashi: The Na'ar will be aggrandized over the Zaken (Malbim - even though the Torah obligates him to honor the Zaken).
Radak: The Na'ar will overpower and be brazen to the Zaken. This is like "v'Rahavam Amal va'Aven" (Tehilim 90:10). This is like Yonason translates, the Na'ar will rule over the Zaken.
Radak (citing Chagigah 14a): One who is Menu'ar (emptied) of Mitzvos will be brazen to one who is full of Mitzvos like a pomegranate [is full of seeds].
Why does it say "veha'Niklah ba'Nichbad"?
Rashi: This is understood simply (the disgraced will be haughty over the honored). Malbim - this is against nature, that the disgraced is humble to the honored.
Rashi (from Chagigah 14a): This is one whose severe [sins] seem to him light - he will be haughty over one whose light [sins] seem to him severe.