not admitting of penetration or passage into or through; "an impenetrable fortress"; "impenetrable rain forests"
6
profound
showing intellectual penetration or emotional depths; from the depths of your being; "the differences are profound"; "a profound insight"; "a profound book"; "a profound mind"; "profound contempt"; "profound regret"
2
dense
hard to pass through because of dense growth; "dense vegetation"; "thick woods"
1
abounding in(p)
abundantly filled; "garden abounding with flowers"; "rich in ideas"; "slums rife with crime"; "the air was thick with snow"
1
inexplicable
incapable of being explained or accounted for; "inexplicable errors"; "left the house at three in the morning for inexplicable reasons"
1
deep
having great spatial extension or penetration; downward ("a deep well"; "a deep dive"; "deep water"; "a deep casserole"); or inward from an outer surface ("a deep gash"; "deep massage"; "deep pressure receptors in muscles"); or backward ("deep shelves"; "