All 10 Uses of

aperture
in
The Count of Monte Cristo

He kept his word; twice a day he cast out, through the barred aperture, the provisions his jailer brought him—at first gayly, then with deliberation, and at last with regret.†
Chpt 15-16

In a moment that part of the floor on which Dantes was resting his two hands, as he knelt with his head in the opening, suddenly gave way; he drew back smartly, while a mass of stones and earth disappeared in a hole that opened beneath the aperture he himself had formed.†
Chpt 15-16

Edmond was obliged to assist him, for otherwise he would not have been able to enter by the small aperture which led to Dantes' chamber.†
Chpt 17-18 *

The explosion soon followed; the upper rock was lifted from its base by the terrific force of the powder; the lower one flew into pieces; thousands of insects escaped from the aperture Dantes had previously formed, and a huge snake, like the guardian demon of the treasure, rolled himself along in darkening coils, and disappeared.†
Chpt 23-24

He remained motionless and pensive, his eyes fixed on the gloomy aperture that was open at his feet.†
Chpt 23-24

But instead of the darkness, and the thick and mephitic atmosphere he had expected to find, Dantes saw a dim and bluish light, which, as well as the air, entered, not merely by the aperture he had just formed, but by the interstices and crevices of the rock which were visible from without, and through which he could distinguish the blue sky and the waving branches of the evergreen oaks, and the tendrils of the creepers that grew from the rocks.†
Chpt 23-24

The aperture of the rock had been closed with stones, then this stucco had been applied, and painted to imitate granite.†
Chpt 23-24

The aperture was already sufficiently large for him to enter, but by waiting, he could still cling to hope, and retard the certainty of deception.†
Chpt 23-24

their prescriptive right of carrying their victims through the routine regularly laid down, and as regularly followed by them, but dragged the unconscious visitor to the various objects with a pertinacity that admitted of no appeal, beginning, as a matter of course, with the Lions' Den, and finishing with Caesar's "Podium,"), to escape a jargon and mechanical survey of the wonders by which he was surrounded, Franz ascended a half-dilapidated staircase, and, leaving them to follow their monotonous round, seated himself at the foot of a column, and immediately opposite a large aperture, which permitted him to enjoy a full and undisturbed view of the gigantic dimensions of the majestic ruin.†
Chpt 33-34

Some few minutes had elapsed, and the stranger began to show manifest signs of impatience, when a slight noise was heard outside the aperture in the roof, and almost immediately a dark shadow seemed to obstruct the flood of light that had entered it, and the figure of a man was clearly seen gazing with eager scrutiny on the immense space beneath him; then, as his eye caught sight of him in the mantle, he grasped a floating mass of thickly matted boughs, and glided down by their help to within three or four feet of the ground, and then leaped lightly on his feet.†
Chpt 33-34

Definition:

an opening -- especially a small one that controls the amount of light admitted for a camera or microscope

or:

the measured diameter of the opening