stop up englanniksi - Sanakirja.org (englanti-englanti)

To fill a hole or cavity, or block an opening or passage, as with a plug.
(photography) To increase the aperture of a photographic lens, moving from an f/stop represented by a higher number to an f/stop represented by a lower number and causing more light to pass into the camera.

So then we . . . scratched around and found an old tin washpan, and stopped up the holes as well as we could.
To stop down means to narrow the aperture; to stop up or open up means to expand it.

Partisiipin perfekti	stopped up
Imperfekti	stopped up
Partisiipin preesens	stopping up
Yksikön kolmannen persoonan indikatiivin preesens	stops up