I. noun 1. an opening, hole, or gap. • the bell ropes passed through apertures in the ceiling.
• the genital aperture of an insect.
2. a space through which light passes in an optical or photographic instrument, especially the variable opening by which light enters a camera. • a refracting telescope with an aperture of 3 inches.
II. derivatives apertural adjective
– origin late Middle English: from Latin apertura, from apert- ‘opened’, from aperire ‘to open’.