Definitions of aperture

1. an opening; usually small

2. a device that controls amount of light admitted

3. an man- made opening; usually small

4. a natural opening in something

5. The act of opening.

6. The diameter of the exposed part of the object glass of a telescope or other optical instrument; as, a telescope of four- inch aperture.

7. An opening; a gap, hole, chasm, or passage.

8. An opening; orifice; hole; cleft.

9. An opening; a gap or passage.

10. An opening; a cleft or gap.