Invisible means there is no visible light. They may give off other electromagnetic radiation, but "light" usually refers to visible light.
Yes.
While black holes give off radio waves, the fact that no light can escape, or be reflected off of, black holes makes them completely invisible to any regular light-capturing device.
yes it does give off light
An incandescent material is one that is capable of becoming so hot that it glows, like a light bulb filament. But a campfire that gives-off flames... or a torch which burns a fuel... to give-off light would simply be considered "candescent."
The phrase 'give off light' means to have a lot of light.
Theoretically if light reflected off you would be same as what it would be if you were not there and shadows did not form you would be invisible. Practically it is impossible.
Planets and Moons only reflect light, they do not 'give off light'.
A rose does not give off light
Diamond can disintegrate if heated enough and will give off carbon dioxide on water and disappear Any of the alkaline metals will burst into flames
The stars give off light
Planets dont give off light therefore all planets dont give off its own light
Things are visible because light bounces off of them and we see the reflected light. Things that are transparent are invisible, because the light passes right through and doesn't bounce off.