Synonyms:
aperture
Meaning: a device that controls amount of light admitted
Usage examples
Was it, I asked myself, a ray from the moon penetrating some aperture in the blind?
It was a jagged fragment of rock which rose some ten feet above the surface of the sand, leaving a narrow aperture between it and the cliff behind.
When I lifted my head I perceived the gradual contraction of its aperture. Its walls, by a gentle incline, were drawing closer to each other, and it was beginning to grow darker.
Here, light was admitted, and smoke discharged, through an aperture in the roof; and here the scent of spirits (for the travelling smugglers, who haunted the Pyrenees, had made this rude people familiar with the use of liquors) was generally perceptible enough.
Refraction analysed out the various constituents of white light and displayed them in the form of a series of overlapping images of the aperture, each of a different colour; this series of images we call a spectrum, and the operation we now call spectrum analysis.
Crawling on all fours, I made steadily but slowly towards them, till at last, raising my head to an aperture among the leaves, I could see clear down into a little green dell beside the marsh, and closely set about with trees, where Long John Silver and another of the crew stood face to face in conversation.