gray out

1. To cover or obscure someone or something in an image with a gray color. A noun or pronoun can be used between "gray" and "out." I don't understand why Tom grayed me out in this picture. Is he upset with me? Someone grayed out the text, so I can't make out what the note says.

2. In computer programming or design, to make some element of a user interface gray to signify that it is not available, not functioning, or has been disabled. A noun or pronoun can be used between "gray" and "out." There is a menu item for motion controls, but the game developers have grayed it out, promising that it will become available in a future update. For some reason, the "Save" button is grayed out on my word processor.

3. To perceive a transient loss or dimming of light, color, or clarity in one's vision due to a lack of oxygen reaching the brain. The intense g-forces caused the astronaut to gray out, but he was thankfully able to maintain consciousness.

4. To cause one to experience such a reduction in vision due to a restriction of oxygen. A noun or pronoun can be used between "gray" and "out." The roller coaster went so fast that it actually grayed me out!