Difficult GRE Words - Group 6

[Esc] (1)
a. impervious to moral persuasion; of hard heart

[Esc] (2)
a. impossible or difficult to perceive by the mind or senses

[Esc] (3)
a. cannot be penetrated or affected, immune

[Esc] (4)
a. urging; demanding; expressing earnest entreaty

[Esc] (5)
v. dispute or contradict, often in insulting way; challenge

[Esc] (6)
a. recently begun; imperfectly formed or developed; elementary

[Esc] (7)
v. teach and impress by frequent repetitions

[Esc] (8)
a. cut in the edge into points or inequalities, like teeth; having an uneven, irregular border

[Esc] (9)
a. poor; experiencing want or need; impoverished

[Esc] (10)
a. incapable of being exhausted, emptied, or used up; unfailing; not to be wasted or spent