aperture priority noun[before a noun]1 •A setting in many professional-grade and advanced-amateur-grade cameras which allows a photographer to manually set the aperture setting of an exposure while the camera then automatically selects the correct shutter speed for that exposure.For landscapes, still lifes, portraits and the like, you'll want an aperture-priority camera. It lets you set the lens opening, while it sets the shutter speed automatically. — 1978
