We could call it "modified natural light" 🙂 of course opposite to "pure natural light" ! Just kidding a little bit of course, I'm not pragmatic at all!
Thanks PKR for bringing us your knowledge of the way many Pros work with light, always interesting.
At the end isn't the light the main component of photography ?
Eye of the Wind - Marshall Bennett - Laughlan Islands - New Guinea_4 by Life in Shadows, on FlickrSure, those would count as natural (non-artificial) light in my book. But what do I know, I'm just some schmuck on the internet. 😉
Perhaps we could classify scrims, reflectors, parachute cloths and the like to be light modifiers? And modifiers could also be used with artificial light sources, like they often are with umbrella strobes and flash softboxes...?

Life in Shadows Eye of the Wind - Marshall Bennett - Laughlan Islands - New Guinea_6 by Life in Shadows, on Flickr

Nikon FM2n, AI Nikkor 50mm f/1.8S, Ultrafine eXtreme 400, developed in LegacyPro L110 at 1:31 for 5.5 minutes.
2020.08.11 Roll #254-05057-positive.jpg by dourbalistar, on Flickr
Hi dourbalistar, really like this shot. As for the lens you used, you have listed AI Nikkor 50mm f/1.8S Can you share with us what lens that is, I am not familiar with a Nikon 50mm f1.8S. Have not seen that "S" suffix with any Nikkor lens. Thanks.
Best,
-Tim