n. | 1. | The act of opening. |
2. | An opening; an open space; a gap, cleft, or chasm; a passage perforated; a hole; | |
3. | (Opt.) The diameter of the exposed part of the object glass of a telescope or other optical instrument; |
Noun | 1. | ![]() |
2. | aperture - a natural opening in something | |
3. | aperture - an man-made opening; usually small |