1)
What is the meaning of "Zomem"?
1.
Radak: He plots.
2)
What is the meaning of "v'Chorek"?
1.
Metzudas Tziyon: It is grinding the teeth amidst anger.
3)
When does the Rasha gnash his teeth?
1.
Radak: It is when he thinks that he will fulfill his intent [to harm the Tzadik].