aperture
/ˈæpəˌtjʊə(r)/noun
1- chiefly technical an opening, hole, or gap〈主技〉开口, 孔, 缝隙：
the bell ropes passed through apertures in the ceiling.
敲钟绳从天花板上的缝隙中穿过。
1.1
- a space through which light passes in an optical or photographic instrument, especially the variable opening by which light enters a camera（光学仪器或照相设备上的）孔径（尤指照相机上可调节的光圈）。
词源
late Middle English: from Latin apertura, from apert- 'opened'， from aperire 'to open'.