8 letters · 10 points in Scrabble
noun a device that controls amount of light admitted
noun a natural opening in something
noun an man-made opening; usually small
originFrom late Middle English, from Latin apertūra (“an opening”), from aperiō (“to uncover, make or lay bare”) + -tūra (“-ure”, action noun suffix). Doublet of overture and apertura.
Etymology from Wiktionary, CC BY-SA 3.0